How to Check if Your Car Frame Was Properly Realigned

A car can look immaculate after an accident repair and still have an alignment problem underneath. Proper frame realignment is about far more than straight-looking panels: the chassis or unibody needs to sit within the correct manufacturer dimensions, the suspension geometry must work as intended, the wheels should track correctly, and the vehicle should behave predictably on the road.

The quick version: after a structural repair, look for consistent panel and wheel-arch gaps, doors and the bonnet opening normally, an even vehicle stance, a centred steering wheel, straight tracking and normal tyre wear. Check the underside for obvious distortion or questionable repair work. For anything beyond these basic observations, ask the repairer for evidence that chassis measurement points and frame dimensions were compared with the manufacturer's specifications. A professional measurement report is much stronger evidence of proper frame alignment than appearance alone.

The important distinction: wheel alignment and frame alignment are related, but they are not the same thing. A wheel alignment adjusts suspension geometry. Frame realignment corrects the underlying vehicle structure. If the structure is still distorted, simply adjusting the wheels does not necessarily solve the cause.

Why Correct Frame Alignment Matters After an Accident

Following a significant impact, collision damage can travel much farther through a vehicle than the dent or damaged panel you can see.

Energy can pass through frame rails, crumple zones, suspension mounting points and other structural areas. Depending on the severity and direction of the impact, the result might be a bent frame, chassis twist, lateral distortion, wheelbase discrepancy or deformation around important mounting and reference points.

That is why a thorough insurance repair should not be judged purely by how good the paint and body panels look when the car comes home.

Modern repair work can make accident damage remarkably difficult to spot. A well-finished bumper, wing or quarter panel tells you about the visible repair; it does not, by itself, prove that the vehicle's structural alignment has returned to specification.

Correct car frame alignment matters because the underlying structure establishes where other components sit in relation to one another. If those relationships are wrong, problems can show themselves through:

• uneven tyre wear;

• an off-centre steering wheel;

• the vehicle pulling to one side;

• inconsistent wheel arch gaps;

• poor or unstable handling;

• doors, the bonnet or boot fitting incorrectly;

• unusual vibration or noises;

• uneven vehicle height;

• incorrect suspension geometry; and

• abnormal straight-line tracking.

Some symptoms can have causes completely unrelated to vehicle frame damage, of course. A car pulling left does not automatically have a twisted chassis. Tyres, brakes, suspension components, road camber and ordinary wheel alignment faults can produce similar behaviour.

The objective is therefore not to diagnose a bent chassis from one symptom. It is to build a picture from several checks and, where structural damage has been repaired, confirm that picture with accurate measurements.

Frame Alignment vs Wheel Alignment: Know What You're Checking

This is an easy distinction to miss.

Wheel alignment concerns the position and angles of the wheels, including values such as toe, camber and caster. These settings form part of the vehicle's suspension and steering geometry.

Frame or chassis alignment concerns the physical structure to which many of those components ultimately relate.

Think of it this way:

1. The frame, chassis or unibody provides the structural foundation.

2. Suspension mounting points and subframes locate mechanical components.

3. The suspension positions the wheels.

4. Wheel alignment fine-tunes the geometry at the wheels.

If the structural foundation has moved during an accident, the rest of the geometry can be affected.

This is one reason post-collision work can involve considerably more than cosmetic refinishing. Spray Shack's wider range of vehicle repair services illustrates how body and accident repairs can encompass different areas of a vehicle rather than being a single isolated process.

Can a Car Have Good Wheel Alignment but a Previously Damaged Frame?

Potentially, yes.

A wheel alignment printout can provide useful information about camber, caster, toe and sometimes thrust angle, but it should not automatically be treated as a substitute for structural measurement following significant frame straightening.

Imagine, for example, that a suspension component or its mounting relationship has changed. It may be possible to bring certain adjustable alignment values within an acceptable range while another part of the body shell or chassis remains outside its intended dimensional position.

Conversely, unusual wheel alignment readings don't prove that frame straightening was performed incorrectly. Worn suspension bushes, bent arms, damaged wheels and other components can influence the readings.

Context matters.

For a car that has undergone structural accident repairs, the stronger question is:

Does the repaired structure match the relevant manufacturer specifications at its designated measurement and datum points?

That gets much closer to establishing whether the frame was properly realigned.

Check 1: Start With the Body — Panel Gaps Tell a Story

Before getting underneath the vehicle or thinking about laser measurement systems, simply stand back and look.

A careful visual frame inspection starts with the relationship between the exterior panels. Manufacturers design doors, wings, bonnets, boots, bumpers and other panels to meet with reasonably consistent gaps. After collision repair, conspicuously uneven panel gaps can indicate that something is not sitting where it should.

Look along both sides of the vehicle in good daylight rather than concentrating solely on the area that was originally damaged.

Compare Left Against Right

Useful areas to examine include:

• bonnet-to-wing gaps;

• door-to-wing gaps;

• gaps between front and rear doors;

• door-to-quarter-panel alignment;

• boot or tailgate gaps;

• bumper-to-wing alignment; and

• the position of each wheel within its wheel arch.

You're looking for symmetry and consistency, not microscopic perfection.

Cars leave the factory with tolerances, and panel gaps can vary. Panels themselves may also have been removed, replaced or adjusted during a repair. One slightly different gap therefore isn't proof of a misaligned frame.

Several discrepancies concentrated around the repaired area deserve more attention.

For examples of the visual standard achievable through professional body repair and refinishing, Spray Shack's previous repair work provides useful context for what to examine when assessing the finished exterior.

Open Every Door, the Bonnet and the Boot

Don't just look at the gaps. Use the panels.

Open and close each door normally. You should not need to lift a door, slam it excessively or push it sideways to persuade the latch to engage.

Then check the bonnet and boot or tailgate.

Pay attention to:

• resistance that wasn't present before the accident;

• a latch that no longer lines up naturally;

• panels rubbing against neighbouring bodywork;

• a door appearing to drop when opened;

• the bonnet sitting noticeably higher on one side; or

• a boot/tailgate that needs unusual force to latch.

Doors not closing properly can be associated with structural misalignment, but once again, don't jump straight to a frame diagnosis. Hinges, latches and individual panels can require adjustment independently of the chassis.

What matters is the pattern of evidence.

If several openings have changed after a collision, the body has obvious asymmetry and the vehicle also displays driving or tyre-wear symptoms, there is much more reason to investigate the structural dimensions.

Check 2: Examine How the Car Sits

Next, park the car on genuinely level ground.

This sounds almost too simple, but a sloping driveway can make a perfectly straight car appear to lean. Tyre pressures should also be checked first, because a significantly underinflated tyre can distort your visual comparison.

Stand several metres behind the vehicle, then repeat the observation from the front.

Does one corner appear lower? Does the body lean? Is there an obvious difference in the amount of space above corresponding tyres?

An uneven vehicle height can point towards a suspension issue, damaged spring, incorrect component, distorted mounting area or structural problem. What it cannot do is identify the cause on its own.

Compare the Wheel Arch Gaps

Look at corresponding wheels from the side.

On an undamaged, correctly assembled car, the wheels should occupy broadly corresponding positions in their arches. A noticeable fore/aft difference on one side may warrant investigation, particularly after a significant accident.

This is where concepts such as wheel setback, wheelbase discrepancy and chassis squareness start becoming relevant.

For a simple initial comparison:

1. Put the steering wheel straight.

2. Park on flat, level ground.

3. Confirm that tyre pressures are appropriate.

4. Look at each wheel's fore/aft position within its arch.

5. Compare the left side with the equivalent position on the right.

6. Note differences rather than immediately trying to diagnose them.

Do not assume that matching wheel-arch gaps constitute a chassis measurement. Exterior panels can themselves be adjusted or replaced.

This is an observational check—a reason to investigate further, not dimensional proof.

Check 3: Look Underneath for Evidence of Remaining Damage

The underside can reveal clues that polished exterior paint cannot.

You should only inspect areas that can be seen safely. Never crawl underneath a vehicle supported only by a jack. If proper lifting equipment and safe support aren't available, leave the detailed underbody inspection to a professional.

From safely accessible positions, look for obvious signs of undercarriage damage, including:

• visibly kinked or buckled structural sections;

• distorted frame rails or chassis rails;

• unusual creases;

• cracks;

• fresh or inconsistent weld points;

• unexplained repair marks;

• heavy scraping around a previously damaged area;

• coatings that differ markedly from the surrounding finish; or

• corrosion affecting an older structural repair.

On a repaired vehicle, fresh welds aren't automatically bad news. Structural collision repair can legitimately involve welding where the manufacturer's repair procedure permits it.

The question is what was repaired, how it was repaired, and whether the procedure complied with the appropriate repair specification.

Similarly, mismatched paint, seam sealer or underbody coating can tell you that an area has received attention, but it doesn't prove that the repair was poor.

If you're assessing the quality of previous work rather than attempting to diagnose it yourself, information about the repairer can also be useful. Knowing who carried out the work and their approach gives context that a quick visual inspection alone cannot provide.

What Does a Bent or Twisted Frame Actually Look Like?

People often imagine a bent frame as something spectacularly obvious—a chassis rail folded in half or a car visibly sitting crooked.

Serious deformation certainly can look like that. But not every structural alignment problem is dramatic.

Depending on the vehicle's construction and impact, technicians may be concerned with different forms of frame deformation, including longitudinal or lateral movement, chassis twist, sag, sway or localised damage around structural sections and mounting points.

A twisted frame can involve a difference in height or plane between reference locations. A lateral displacement can move structural points sideways. A front or rear impact may alter longitudinal dimensions. Localised damage may affect a frame rail or suspension mounting location without making the entire vehicle visibly crooked.

Modern unibody vehicles complicate the casual inspection further because the structural body shell itself performs much of the work traditionally associated with a separate chassis.

That's why appearances have limits.

If you want to check whether the chassis is straight with confidence, eventually you need measurements.

Before reaching that stage, however, there are several surprisingly revealing checks you can make from the driver's seat.

Check 4: Pay Attention to the Steering Wheel

After the vehicle has been repaired and wheel alignment completed, note the steering wheel position while travelling straight ahead on a suitable, reasonably level road.

Is it centred?

An off-centre steering wheel is one of the more noticeable post-repair symptoms. It may be associated with wheel alignment or steering adjustment rather than frame distortion, but after significant collision damage it deserves attention.

The important question is whether it appears alongside other symptoms.

For example:

Off-centre steering wheel alone:Could simply indicate an alignment or steering-centering issue.

Off-centre wheel + vehicle pulling + unusual tyre wear:A stronger reason to have the suspension geometry investigated.

Off-centre wheel + pulling + visibly different wheel position + previous structural repair:More reason still to request a proper post-repair structural inspection and measurement.

This process of combining evidence is far more useful than treating individual symptoms as a DIY diagnosis.

Check 5: Does the Car Track Straight?

A correctly repaired car should feel predictable.

During a careful test drive, pay attention to whether it naturally tracks straight, whether the steering feels consistent and whether the car appears to require continuous correction.

A vehicle pulling to one side can be relevant, but road camber matters. Many UK roads slope towards the kerb for drainage, so a mild tendency on one particular road isn't a useful structural test.

Instead, consider whether the behaviour is persistent across suitable roads.

Watch for:

• persistent pulling;

• unstable steering;

• unusual steering effort;

• a tendency to wander;

• steering that feels different turning left versus right;

• unexplained vehicle vibrations; and

• a sensation that the rear of the vehicle isn't following the front normally.

That last behaviour is sometimes informally described as crab walking, dog tracking or vehicle crabbing. In obvious cases, the vehicle appears to travel with its rear axle or body at an angle relative to the direction of travel.

It can be associated with alignment, axle, suspension or structural problems and warrants professional investigation.

If you're deciding who should assess accident repair concerns, previous customer experiences can provide another piece of the picture; Spray Shack publishes customer testimonials covering its repair and bodywork services.

Check 6: Read the Tyres

Tyres quietly record what's happening between the vehicle and the road.

Run your eyes across the tread of all four—not just the two nearest the repaired area. You're looking for uneven tyre wear or a pattern that differs markedly from one side of the car to the other.

Potential patterns include:

• excessive wear on one shoulder;

• different inner and outer shoulder wear;

• feathering across tread blocks;

• one tyre wearing substantially faster than its opposite number; or

• abnormal wear appearing unusually soon after the repair.

These patterns can relate to toe, camber, worn suspension parts, tyre pressure and many other factors. They are not a frame-alignment test in isolation.

But imagine this sequence:

The car suffered structural collision damage. It underwent frame straightening. Afterwards the steering wheel sits off-centre, the car persistently pulls, one wheel looks slightly displaced in its arch and a tyre develops abnormal shoulder wear.

At that point, asking for a geometry check and evidence of the original frame alignment verification would be entirely reasonable.

The visible checks have done their job.

The next step is to stop guessing and start measuring.

Why Visual Checks Can't Confirm Proper Frame Realignment

Everything covered so far can help you identify warning signs, but none of it conclusively establishes proper frame alignment.

A car can have beautifully even panel gaps because replacement panels were carefully adjusted around an imperfect structure. Conversely, a structurally correct vehicle can have a poorly adjusted door or bumper that creates an ugly gap.

Likewise:

• straight tracking does not prove every chassis datum is correct;

• an alignment printout doesn't necessarily establish frame squareness;

• even tyre wear doesn't prove the body shell matches OEM dimensions;

• good paintwork cannot confirm structural integrity; and

• the absence of obvious underbody damage doesn't rule out dimensional deviation.

For a vehicle that has undergone meaningful chassis straightening or frame realignment, objective dimensional measurement is the stronger evidence.

That means comparing specified reference points on the repaired structure against the vehicle manufacturer's dimensional data and permitted tolerances.

And that is where chassis measurement, diagonal measurements, datum points, laser systems and professional frame-alignment equipment enter the picture.

Check 7: Measure the Wheelbase — But Know Its Limits

Once the visual and driving checks are complete, measurement is where frame alignment verification becomes much more meaningful.

One useful starting point is the vehicle's wheelbase: broadly, the distance between the centres of the front and rear wheels on the same side of the car.

Following structural damage, a noticeable wheelbase discrepancy between the left and right sides can be a clue that something is wrong. Possible causes include suspension damage, wheel setback, movement around suspension mounting points or residual structural damage.

A basic comparison involves measuring as consistently as possible between corresponding wheel hub centres on each side.

If one side differs significantly from the other, don't immediately conclude that the chassis is bent. What you've found is a discrepancy requiring explanation.

Why Wheelbase Measurement Isn't Enough

Wheelbase tells you something about longitudinal positioning, but it cannot tell you everything about chassis alignment.

A structure could theoretically have similar left and right wheelbase measurements while still suffering from:

• lateral displacement;

• chassis twist;

• incorrect frame rail alignment;

• distorted suspension mounting points;

• poor chassis flatness;

• incorrect frame symmetry; or

• movement elsewhere in the body shell.

That is why professional structural measurement uses multiple known locations rather than relying on a tape measure between four wheels.

The real question isn't simply "Are both sides approximately the same length?"

It is:

Are the relevant points in the correct three-dimensional positions specified by the vehicle manufacturer?

That distinction matters.

Check 8: Understand Diagonal and Cross Measurements

One of the traditional ways to assess chassis squareness is through diagonal measurements.

Imagine four known reference points forming a rectangle beneath the vehicle. If you measure diagonally from the front-left point to the rear-right point, then compare that distance with the opposite diagonal, a significant difference may indicate that the structure isn't square.

This is the principle behind a cross-diagonal measurement.

In simplified terms:

1. Identify equivalent manufacturer-approved reference points.

2. Measure from one front reference point to the opposite rear point.

3. Repeat across the opposite diagonal.

4. Compare the results.

5. Compare both with the correct body dimensions where available.

Equal diagonals can provide evidence of squareness between those particular points.

But—and this is important—equal diagonal measurements do not prove that the entire chassis is straight.

A structure can potentially be square in one plane while being distorted in another. Height differences, local frame deformation and chassis twist require additional measurements.

This is why DIY cross measurement is useful primarily as an investigative check rather than a substitute for professional chassis measurement.

What Are Datum Points?

You'll often encounter the terms datum points, reference points or chassis measurement points when structural alignment is being discussed.

These are defined locations on the vehicle structure that technicians can use to establish whether important sections of the body or chassis are positioned correctly.

Depending on the vehicle and measuring system, these can include locations associated with:

• frame or chassis rails;

• crossmembers;

• suspension mounting points;

• subframe mounting locations;

• control-arm mounting points;

• structural apertures; and

• other manufacturer-defined areas of the body shell.

The technician isn't simply deciding whether the car looks straight.

They're establishing where a point actually sits in space and comparing that location with where the manufacturer's dimensional information says it should sit.

That gives frame measurement an objective baseline.

Length, Width and Height: Frame Alignment Is Three-Dimensional

A common mistake is to think of a damaged chassis as something that is merely "bent sideways."

Collision forces aren't that obliging.

Structural movement can occur longitudinally, laterally and vertically. Depending on the accident, the technician may therefore need to establish three-dimensional relationships between reference points.

Think in terms of three basic directions:

Dimension	What it can help reveal
Length	Fore/aft displacement, shortening, stretching or wheelbase-related discrepancies
Width	Lateral displacement, sway and incorrect cross-body positioning
Height	Chassis twist, sagging, raised/lowered structural points and vertical distortion

A proper three-dimensional frame measuring process can therefore reveal problems that a simple tape measurement across the floor may miss.

This becomes especially important when checking chassis flatness.

If one structural point is too high or too low relative to the intended datum plane, the left-to-right and front-to-rear distances could look plausible while the structure is still wrong in three-dimensional space.

That is one reason modern collision repair measurement is so much more sophisticated than simply checking whether two diagonals match.

Check 9: Compare Measurements With Manufacturer Specifications

Measurements only become genuinely useful when you know what the numbers are supposed to be.

If a technician tells you that two chassis points are "about 1,300 mm apart," that number means very little by itself.

Is 1,300 mm correct?

Should it be 1,298 mm? 1,305 mm? Are the points being measured the correct ones? What tolerance applies? What is the specified height relative to the datum plane?

For proper post-repair verification, frame dimensions should be evaluated against the appropriate manufacturer specifications or recognised vehicle-specific dimensional data.

This is one of the strongest distinctions between an approximate DIY check and professional structural measurement.

Ask About OEM Body Dimensions

For a vehicle that has undergone substantial structural work, useful questions for the repairer include:

• Which reference or datum points were measured?

• What dimensional data were those measurements compared against?

• Were length, width and height checked where required?

• Were measurements taken before and after frame straightening?

• Are the repaired points within the specified dimensional tolerances?

• Is there a frame measurement report available?

That last question can be particularly useful.

A before-and-after frame measurement report, where the equipment and repair process provide one, can give you something far more concrete than "we checked it and it was fine."

It can document the relationship between measured structural locations and the intended specifications.

A straight-looking car is an observation. A structure measured against vehicle-specific dimensional specifications is evidence.

That doesn't mean every minor body repair requires an elaborate chassis report. A scratched door and a structurally damaged accident vehicle are obviously different situations.

But if significant frame straightening was required, dimensional verification becomes much more relevant.

Check 10: Understand What a Chassis Jig Actually Does

The terms chassis jig, jigging system, alignment bench and frame machine can sound intimidating if you've never seen structural repair being performed.

The principle is relatively straightforward.

The vehicle is securely positioned on specialist equipment. Technicians establish the structural condition using known measurement points and, where required, controlled pulling or correction is used to return displaced structural sections towards their specified positions.

The jig or bench provides a controlled platform from which accurate repair work can be performed.

This is substantially different from someone simply looking along a chassis rail and deciding it appears straight.

During proper chassis straightening, the technician needs to understand:

• where the structure has moved;

• the direction of the deformation;

• which structural sections are affected;

• where corrective force should be applied;

• what the manufacturer permits to be repaired;

• which sections may instead require replacement; and

• when the relevant dimensions have returned within specification.

The measurement process and the straightening process therefore work together.

Measure. Correct. Re-measure. Verify.

That final step is crucial.

Getting the structure closer to its original position isn't the same as demonstrating that the completed repair meets the required dimensions.

Check 11: How Laser and Computerized Measuring Systems Help

Professional repair facilities may use a laser measurement system, electronic measuring equipment or a computerized frame measuring system to assess structural dimensions.

Specific equipment varies, but the objective is broadly the same: obtain accurate positional information from designated points on the vehicle and compare it against reference data.

This can make subtle structural discrepancies visible in a way that the naked eye simply cannot.

A computerized chassis measurement can help technicians assess aspects such as:

• longitudinal alignment;

• lateral alignment;

• structural height;

• frame squareness;

• chassis symmetry;

• individual datum-point positions;

• frame rail alignment; and

• relationships between structural and suspension mounting locations.

Some systems can also document measurements during different stages of the repair.

That creates an important distinction between repairing by appearance and repairing by measurement.

What Does a Laser Alignment System Prove?

This requires a little nuance.

The presence of an expensive laser-guided frame machine does not automatically prove that a repair has been completed correctly.

Equipment is a tool.

What matters is that:

1. the correct vehicle data were used;

2. the correct measurement points were identified;

3. measurements were taken accurately;

4. appropriate repair procedures were followed; and

5. final measurements confirmed that relevant structural dimensions were within the required tolerances.

In other words, don't become fixated on whether the repairer uses a particular brand or type of machine.

Ask about the result.

What Should Be on a Frame Measurement Report?

The exact format varies according to the measuring equipment, vehicle and repairer, but a useful measurement report may show the positions or dimensional status of structural points before, during or after repair.

If you've been given one, look for information that identifies:

• the vehicle;

• the measurement/reference points;

• target or specification values;

• actual measured values;

• deviations from those values; and

• final post-repair measurements.

You don't necessarily need to become an expert in reading chassis diagrams.

Ask the technician to explain the report.

A useful conversation might be as simple as:

"Can you show me which structural points were outside specification, what was corrected and where the final measurements confirm that they're now within the required tolerance?"

A reputable professional should be able to explain what the measurements mean in understandable terms.

Keep the report with the rest of the repair documentation, particularly after substantial collision work.

Check 12: Look Beyond the Frame to Suspension Geometry

Once structural alignment is established, attention should also turn to suspension geometry.

This matters because the chassis, suspension and wheels function as a system.

Collision forces can damage:

• control arms;

• steering components;

• hubs;

• struts;

• subframes;

• suspension mounting locations;

• wheels; and

• other geometry-critical components.

Correcting the main body structure doesn't magically straighten a bent suspension component.

Likewise, replacing suspension parts cannot correct a structural mounting point that remains displaced.

After relevant collision repairs, a four-wheel alignment can provide valuable information about how the wheels are positioned relative to one another and the vehicle's intended geometry.

Camber, Caster and Toe

Three terms frequently appear on wheel alignment reports:

Camber describes the inward or outward inclination of a wheel when viewed from the front.

Caster relates to the steering axis when viewed from the side and influences steering behaviour and self-centring.

Toe describes whether corresponding wheels point slightly towards or away from one another when viewed from above.

You'll often see toe described as toe-in or toe-out.

Depending on the vehicle, some values are adjustable and others may not be. If a non-adjustable value remains significantly outside specification following an accident, further investigation may be required to determine whether a component, mounting point, subframe or structural area is responsible.

Again, the alignment data provides evidence to interpret, not an automatic diagnosis.

Don't Ignore the Thrust Angle

The thrust angle describes the relationship between the direction in which the rear wheels effectively push the vehicle and its geometric centreline.

In simple terms, you want the rear of the car to follow the front correctly rather than trying to travel along a slightly different path.

An abnormal thrust relationship can contribute to:

• steering correction;

• an off-centre steering wheel;

• unusual tracking behaviour;

• uneven tyre wear; and

• the impression that the vehicle is travelling slightly sideways.

This connects directly with the earlier warning sign of dog tracking or crab walking.

But an incorrect thrust angle doesn't automatically mean the frame realignment failed. Rear suspension alignment, axle positioning, subframe location, bent components and other factors need to be considered.

What it does provide is another piece of measurable evidence.

Check 13: Make Sure the Subframes and Mounting Points Were Considered

Modern cars frequently use front and/or rear subframes to carry suspension, steering, engine or drivetrain components.

That creates another important consideration following an accident.

You can have a body shell that has been structurally corrected while a damaged or incorrectly positioned subframe continues to affect wheel and suspension geometry.

Conversely, what initially appears to be a chassis-alignment symptom might originate from the subframe or components attached to it.

A thorough post-collision assessment may therefore need to consider:

body shell → structural mounting points → subframe alignment → suspension components → wheel geometry.

Each layer affects the next.

Areas such as control-arm mounting points, strut or shock tower locations and subframe mounting points can be especially important because small positional changes may translate into geometry changes at the wheel.

This is another reason why the phrase "the frame was straightened" shouldn't be treated as the end of the conversation.

The goal is a vehicle whose repaired structural and mechanical systems work together as intended.

What About a Cat S Vehicle?

In the UK, Category S structural damage means an insurer has classified a written-off vehicle as having sustained damage to a structural part of the vehicle, but one that can potentially be repaired.

A Cat S vehicle isn't automatically unsafe simply because of that classification.

The important issue for a prospective owner is the quality and completeness of the repair.

When assessing a previously structurally damaged vehicle, documentation becomes particularly valuable. Depending on what is available, you may want to see:

1. photographs showing the original collision damage;

2. details of the structural areas affected;

3. invoices for replacement components;

4. information about the body repair shop that completed the work;

5. structural or frame measurement records;

6. wheel alignment results;

7. photographs taken during the repair; and

8. evidence of subsequent inspections where applicable.

A glossy finish tells you almost nothing about what happened beneath it.

A documented repair history gives you considerably more to work with.

This distinction is particularly important when buying a salvage vehicle or previously repaired structurally damaged car, where you weren't present to see the original damage or repair process.

Check 14: Ask the Repairer These Questions

If your vehicle has undergone structural accident repair, you don't need to walk into the workshop armed with engineering jargon.

A handful of specific questions can reveal far more:

1. Was structural measurement required on my vehicle?

2. Which parts of the chassis or body structure were affected?

3. Were the frame dimensions compared with vehicle-specific manufacturer data?

4. Were measurements taken after the straightening was completed?

5. Were all relevant points within the specified tolerances?

6. Was the suspension or subframe damaged as well?

7. Was four-wheel alignment carried out afterwards?

8. Can I have copies of the structural measurement and alignment reports?

9. Were OEM repair procedures followed for the affected structural sections?

10. Is there anything about the repaired area that I should continue to monitor?

These questions shift the discussion away from "Does it look straight?" and towards how the repair was actually verified.

And that is precisely where confidence in a structural repair should come from.

A Note on Repair Tolerances

"Straight" does not necessarily mean every measured point must equal a theoretical number to a fraction of a millimetre.

Vehicle manufacturers and professional measuring systems work with specifications and permitted dimensional tolerances. The relevant question is therefore whether the completed repair falls within the acceptable limits for that vehicle and repair procedure.

Those tolerances aren't something to guess from generic measurements found online.

Different models—and sometimes different versions of the same model—can have different structural dimensions and repair requirements.

For that reason, DIY chassis measurement has a clear boundary.

You can identify discrepancies.

You can compare symmetry.

You can spot suspicious symptoms.

You can ask informed questions.

But when the objective is to verify structural alignment following substantial collision repair, vehicle-specific data and suitable professional measuring equipment provide the stronger answer.

The Evidence Chain You Want After Frame Straightening

By this stage, the most reliable way to think about frame realignment is as a chain of evidence rather than one magic test.

Original collision damage↓Structural inspection↓Vehicle-specific datum/reference points identified↓Pre-repair chassis measurements↓Correct repair or frame straightening procedure↓Post-repair structural measurement↓Comparison with manufacturer specifications↓Suspension and steering checks↓Four-wheel alignment / geometry verification↓Road test and final inspection

The stronger that chain is, the less you have to rely on assumptions.

A vehicle that merely looks straight is one thing.

A vehicle whose structure has been measured, repaired correctly, re-measured against the appropriate specifications, aligned and road-tested gives you a much more meaningful basis for judging the repair.

And there is one final part of the process that shouldn't be overlooked: deciding when the warning signs justify an independent inspection, what paperwork you should keep, what safety-related systems may need checking after a collision, and what to do if you suspect the frame is still out of alignment.

Check 15: Know When to Get an Independent Structural Inspection

By now, you've checked the visible body alignment, looked for suspicious panel and wheel-arch gaps, considered the car's stance, paid attention to steering and tracking, inspected the tyres and understood what professional chassis measurement should establish.

So what happens if something still doesn't feel right?

Don't keep trying to prove the problem from your driveway.

If a vehicle has undergone significant frame straightening or chassis straightening and continues to show several alignment-related symptoms, an independent post-repair inspection can be the sensible next step.

That becomes particularly important when you notice a combination of warning signs such as:

• persistent pulling to one side;

• an off-centre steering wheel after wheel alignment;

• abnormal or rapidly developing tyre wear;

• obvious wheel setback;

• inconsistent wheel-to-arch alignment;

• unexplained vehicle crabbing or dog tracking;

• noticeably uneven vehicle height;

• several misaligned body panels;

• doors, bonnet or boot no longer operating normally;

• unusual vibration or unstable steering;

• suspicious underbody repair marks;

• unexplained differences in chassis dimensions; or

• alignment values that repeatedly cannot be brought within specification.

One symptom isn't necessarily evidence of an improperly realigned frame.

Several related symptoms following known structural damage deserve more attention.

A professional structural inspection can help separate a genuine chassis problem from faults involving tyres, wheels, steering, suspension components or ordinary alignment.

What Should an Independent Inspection Include?

The appropriate scope depends on the vehicle and its repair history, but following significant collision damage you may want the inspection to consider:

1. visible structural and underbody condition;

2. body panel fit and symmetry;

3. chassis and body-shell reference points;

4. frame rail condition;

5. suspension mounting points;

6. subframe positioning;

7. wheelbase and relevant dimensional relationships;

8. steering and suspension geometry;

9. tyre-wear patterns;

10. four-wheel alignment data;

11. previous welds or structural repair areas; and

12. comparison with applicable vehicle-specific dimensional information.

If there is genuine concern about residual structural damage, ask whether electronic, laser or computerized chassis measurement is appropriate.

You are trying to move from suspicion to measurable evidence.

Check 16: Don't Ignore the Original Repair Documentation

Paperwork may not be as satisfying as crawling around the car with a torch, but it can tell you things a visual inspection cannot.

After substantial accident repair, keep whatever repair documentation is available.

Depending on the circumstances, this could include:

• the original repair estimate;

• photographs of the collision damage;

• photographs taken during dismantling;

• parts invoices;

• details of structural sections repaired or replaced;

• chassis or frame measurement reports;

• wheel alignment printouts;

• repair invoices;

• insurer documentation; and

• any inspection or repair certificate provided.

These records can help establish what actually happened to the vehicle.

For example, knowing that a front bumper, headlamp and wing were replaced tells a very different story from documentation showing repairs to a chassis rail, structural crossmember or suspension mounting area.

Before-and-After Measurements Are Particularly Useful

Where structural measurement was required and the equipment provides reports, before-and-after frame measurements can be especially informative.

A pre-repair report may identify which chassis measurement points were displaced.

The post-repair measurement can then demonstrate whether those points were returned within the applicable specification.

That provides a logical audit trail:

Damage identified → measurements recorded → structural correction performed → measurements repeated → final position verified.

If you don't understand the figures, ask for them to be explained rather than assuming that a sheet full of green numbers automatically means everything is correct.

Ask:

"Can you show me which points were affected and how the final measurements compare with the manufacturer's specifications?"

That's a reasonable question after meaningful structural work.

Check 17: Confirm the Wheel Alignment Was Done at the Right Stage

Wheel alignment is most useful when the structure and relevant mechanical components have already been correctly repaired.

Consider the sequence.

If a collision has caused frame deformation and damaged suspension components, performing a four-wheel alignment before those underlying issues have been corrected would not solve them.

A more logical repair sequence is broadly:

Structural assessment → structural repair → structural measurement verification → suspension/steering repair → wheel alignment → road test.

The exact procedure naturally depends on the vehicle and type of damage.

What matters is that wheel alignment after frame repair should verify the geometry of a vehicle whose underlying structural and mechanical problems have already been addressed.

Keep the Alignment Printout

If you receive a wheel alignment report, keep it.

The report may show measurements such as:

• front and rear toe;

• total toe;

• camber angle;

• caster angle, where measured;

• thrust angle; and

• other vehicle-specific geometry values.

Look for values that remain outside specification, particularly if the technician says they cannot be adjusted.

An out-of-specification reading doesn't automatically mean the body shell is distorted. A bent suspension component or incorrectly positioned subframe could be responsible.

But unexplained geometry that remains outside specification after collision repair deserves investigation.

Check 18: Consider ADAS After Collision Repairs

There is another aspect of modern accident repair that can easily be overlooked: Advanced Driver Assistance Systems, usually shortened to ADAS.

Depending on the vehicle, systems such as lane assistance, adaptive cruise control, autonomous emergency braking, parking assistance and other driver aids can rely on cameras, radar units or sensors whose operation depends upon correct positioning and calibration.

Collision repair can involve areas where these components are mounted or can change vehicle geometry relevant to their calibration.

For vehicles equipped with applicable systems, ADAS calibration after collision repair may therefore form part of returning the vehicle to the required operating condition.

The exact calibration requirements are vehicle-specific. They can depend on what was damaged, removed, replaced or adjusted.

So rather than assuming every repaired vehicle requires the same procedure, ask the repairer whether your vehicle has ADAS equipment affected by the repair and whether the manufacturer's procedure specifies calibration.

Structural alignment, wheel geometry and electronic driver-assistance systems increasingly belong to the same wider conversation: putting the whole vehicle back into its intended condition, not merely making the damaged corner look new again.

Check 19: Test Drive the Car Again After the Repairs Are Complete

A final test drive is not a substitute for chassis measurement, but it remains an important real-world check.

Choose appropriate roads and pay attention to how the vehicle behaves under ordinary driving conditions.

You are not trying to perform aggressive manoeuvres or "stress test" the repair.

Instead, notice whether the vehicle feels natural.

During the Drive, Pay Attention To:

• whether the steering wheel remains centred;

• whether the car tracks predictably;

• persistent pulling on suitable roads;

• steering vibration;

• unusual noises;

• steering that feels nervous or unstable;

• whether the vehicle requires constant correction;

• changes under gentle braking;

• unexpected behaviour through ordinary bends; and

• whether anything feels noticeably different from before the accident.

If something feels wrong, write down what happens and when.

"Car feels weird" is difficult for a technician to investigate.

"At approximately 40–50 mph on a level road, the steering wheel sits slightly clockwise and the car consistently drifts left" gives them something much more useful to work with.

The same applies to noises and vibrations.

Note whether they occur:

• at a particular speed;

• while accelerating;

• while braking;

• while turning;

• over uneven surfaces; or

• continuously.

Specific observations make diagnosis easier.

Check 20: Recheck the Tyres After You've Driven the Car

Some alignment problems become clearer with mileage.

A freshly repaired vehicle can leave the workshop with four tyres that appear perfectly normal simply because there hasn't been enough driving for an abnormal wear pattern to develop.

Periodically inspect the tread during the weeks and months following significant collision repairs.

Look for changes across the width of each tyre and compare equivalent tyres from side to side.

Pay particular attention to:

Inner-edge wear — potentially associated with geometry such as excessive negative camber or toe conditions.

Outer-edge wear — potentially related to geometry, tyre pressure or driving conditions.

Feathering — tread blocks may feel smoother in one direction and sharper in the other, which can be associated with toe-related issues.

One tyre deteriorating unusually quickly — worth investigating, particularly if accompanied by pulling, steering or tracking symptoms.

Tyre wear has many possible causes, so don't use it to diagnose frame deformation on its own.

Its value comes from correlation.

If abnormal wear appears alongside other post-repair symptoms, the evidence for a geometry problem becomes stronger.

Can You Check Frame Alignment at Home?

You can perform useful checks at home.

You generally cannot reproduce a complete professional structural measurement without the correct equipment, dimensional data and expertise.

That distinction is worth preserving.

Checks a Car Owner Can Reasonably Make

You can:

• compare panel gaps;

• open and close doors, bonnet and boot;

• compare wheel positions visually;

• check tyre pressures;

• inspect tyre-wear patterns;

• observe whether the vehicle sits level;

• look for safely visible underbody damage;

• note steering-wheel position;

• assess straight-line behaviour during normal driving;

• compare accessible measurements cautiously; and

• review repair and alignment documentation.

These checks can reveal reasons to investigate further.

Checks Better Left to Professionals

Professional equipment and expertise become more important when assessing:

• exact chassis datum points;

• OEM body dimensions;

• three-dimensional frame measurements;

• chassis flatness;

• frame rail deformation;

• structural repair tolerances;

• suspension mounting-point displacement;

• subframe alignment;

• computerized chassis measurement;

• laser measurement;

• structural weld integrity; and

• whether a repair follows vehicle-specific procedures.

There is also a simple safety consideration.

Do not place yourself underneath an inadequately supported vehicle to obtain measurements.

No chassis check is worth the risk of a vehicle falling from a jack.

DIY Measurements vs Professional Frame Measurement

Here's the practical distinction:

DIY / owner check	Professional verification
Compare visible symmetry	Measure defined datum points
Observe panel gaps	Compare body dimensions with manufacturer data
Look at wheel position	Measure longitudinal/lateral position
Compare basic wheelbase	Verify vehicle-specific wheelbase dimensions
Look for uneven stance	Measure structural height
Observe tyre wear	Analyse suspension geometry
Notice pulling/tracking	Measure four-wheel alignment and thrust angle
Inspect accessible underbody areas	Examine structural sections on suitable equipment
Review paperwork	Produce/interpret structural measurement data
Identify warning signs	Determine whether dimensions meet specification

Both have value.

They simply answer different questions.

The owner checks help answer:

"Is there anything here that concerns me?"

Professional measurement helps answer:

"Is the repaired structure actually where it is supposed to be?"

What If the Car Still Pulls After Frame Realignment?

Don't immediately assume the frame realignment has failed.

Pulling can be caused by numerous factors, including:

• tyre pressure differences;

• tyre construction or wear;

• brake drag;

• wheel alignment;

• road camber;

• bent suspension components;

• worn bushes or joints;

• steering issues;

• subframe position; or

• structural misalignment.

The sensible approach is diagnostic rather than assumptive.

First check the easy variables, particularly tyres and pressures. If the problem remains, have the wheel alignment and suspension inspected.

If the vehicle has a history of substantial structural repair and conventional causes don't explain the behaviour, then revisit the structural alignment and associated measurement data.

This is why keeping the original measurement report can be so valuable.

It provides a baseline rather than forcing everyone to start from scratch.

What If the Steering Wheel Isn't Straight?

Again, an off-centre steering wheel does not automatically equal a bent frame.

It may simply require the wheel alignment and steering centring to be corrected.

But if the steering wheel remains off-centre after alignment—or keeps becoming off-centre—ask why.

Particularly relevant accompanying symptoms include:

• persistent pulling;

• abnormal toe readings;

• unusual thrust angle;

• uneven tyre wear;

• visibly different wheel setback;

• unexplained suspension geometry; and

• previous structural collision damage.

The more of these symptoms occur together, the stronger the case for further investigation.

What If the Panel Gaps Still Aren't Even?

Uneven panel gaps after body repair can be frustrating, but they're not automatically evidence of a misaligned frame.

A replacement wing, bonnet, door, bumper or boot lid may simply require further adjustment.

The distinction is whether the problem is localised or structural.

A single poorly fitting bumper corner points towards a very different problem from several apertures and body panels being displaced in corresponding directions.

Consider:

• how many panels are affected;

• whether doors latch naturally;

• whether the wheels appear correctly positioned;

• whether the vehicle sits evenly;

• whether steering and tracking are normal; and

• whether structural measurements confirm the underlying geometry.

Again, look for a pattern.

Warning Signs That Deserve Prompt Professional Attention

Some concerns shouldn't be monitored indefinitely in the hope that they disappear.

Arrange a professional assessment if, following significant accident repair, you encounter persistent or unexplained issues such as:

• severe pulling or unstable steering;

• obvious crab walking;

• substantial uneven tyre wear;

• a wheel visibly displaced in its arch;

• significant difference in vehicle height;

• structural cracking;

• visibly buckled or kinked frame rails;

• suspension geometry that cannot be brought within specification;

• abnormal steering behaviour;

• concerning noises from a structurally repaired area; or

• evidence that important structural work may not have been completed correctly.

If you have reason to doubt the vehicle's roadworthiness or safety, avoid treating the issue as merely cosmetic.

Get it assessed appropriately before continuing normal use.

Structural Integrity Is About More Than Straight Lines

The phrase "straightening the frame" makes structural collision repair sound like a simple exercise in geometry.

There is more to it.

Vehicle structures are engineered to manage loads and collision energy. Crumple zones, structural rails, reinforcements and adjoining sections form part of that system.

Consequently, returning a structural point to its correct dimensional position isn't the only consideration in a proper repair.

The affected material and repair method matter too.

Depending on the vehicle and damaged section, manufacturer repair information may specify whether a component can be:

• straightened;

• repaired;

• partially replaced;

• sectioned at an approved location; or

• replaced completely.

This is why structural integrity and dimensional alignment should be considered together.

A rail being in the right place geometrically doesn't by itself establish that an inappropriate structural repair method wasn't used.

Equally, a properly replaced structural component still needs to be positioned correctly.

Correct material repair + correct structural position + correct geometry = the bigger picture.

Frame Alignment and Crashworthiness

One reason structural repair quality matters is crashworthiness.

The body structure isn't simply a framework that holds the panels in place. It forms part of the vehicle's engineered response to collision forces.

That makes proper repair of structural sections fundamentally different from cosmetic improvement.

Where significant vehicle frame damage has occurred, the aim should be to follow the appropriate repair procedures and restore the affected areas in accordance with the applicable specifications—not merely produce a car that looks straight from ten metres away.

This is also why suspicious shortcuts around repaired welds, heavily distorted rails or structural mounting points deserve professional attention.

If you don't know what repair was carried out, ask.

If the documentation is incomplete and the previous damage was substantial, consider an independent inspection.

How to Check if Your Car Frame Was Properly Realigned: The Final Checklist

Use this as a practical post-repair sequence rather than treating any single item as definitive proof.

• Park the vehicle on level ground and compare its stance from front and rear.

• Compare panel gaps around the bonnet, doors, boot/tailgate, wings and bumpers.

• Open every major panel and check that doors, bonnet and boot operate naturally.

• Compare wheel arch gaps and look for obvious wheel setback.

• Inspect the tyres for abnormal or uneven wear.

• Check safely visible underbody areas for unexplained distortion or questionable repair marks.

• Test drive the vehicle carefully and note pulling, wandering, vibration or unusual noises.

• Check steering wheel centring when travelling straight on an appropriate road.

• Consider wheelbase and diagonal measurements only as preliminary indicators, not definitive structural proof.

• Ask which chassis datum/reference points were measured after structural repair.

• Confirm measurements were compared with vehicle-specific specifications rather than judged visually.

• Request the post-repair frame measurement report, where one was produced.

• Review four-wheel alignment results and investigate unexplained values outside specification.

• Confirm suspension and subframe damage was addressed, where relevant.

• Ask whether applicable ADAS calibration procedures were required and completed.

• Keep the repair documentation and measurement records.

• Arrange an independent structural inspection if several warning signs remain.

The Biggest Mistake: Looking for One Definitive Sign

There isn't one.

A bent frame doesn't always produce obvious crab walking.

Uneven tyre wear doesn't necessarily mean chassis alignment is wrong.

A crooked steering wheel doesn't prove a structural problem.

Uneven panel gaps don't automatically mean frame straightening failed.

And a car that drives perfectly doesn't, by itself, demonstrate that every structural reference point is within specification.

The strongest conclusion comes from multiple layers of evidence.

Layer 1 — Appearance

Are panel gaps, wheel positions and vehicle height broadly consistent?

Layer 2 — Behaviour

Does the vehicle track, steer and handle normally?

Layer 3 — Mechanical Geometry

Are wheel alignment and suspension geometry within the appropriate specifications?

Layer 4 — Structural Measurement

Do the chassis or unibody measurement points match the relevant manufacturer dimensions and tolerances?

Layer 5 — Repair Quality

Was the damaged structure repaired using an appropriate procedure, and is there documentation supporting the work?

When those layers agree, you have a much stronger basis for confidence.

Final Thoughts

Knowing How to Check if Your Car Frame Was Properly Realigned ultimately means knowing where DIY observation ends and proper structural verification begins.

Start with what you can see.

Check panel fit, wheel position, vehicle height and accessible underbody areas. Pay attention to what you can feel: pulling, steering position, vibrations, handling and straight-line tracking. Watch the tyres as mileage accumulates.

Then look beyond symptoms.

After significant structural damage, frame measurements, chassis datum points, suspension geometry, wheel alignment and manufacturer specifications provide much stronger evidence than appearance alone. If a laser measurement system or computerized frame measuring system was used, ask what the final measurements actually showed. If a chassis jig was required, ask how the completed repair was verified.

Most importantly, don't confuse a beautiful cosmetic finish with proof of structural alignment—and don't make the opposite mistake of assuming every imperfect panel gap means the chassis is twisted.

The goal is evidence.

Inspect it. Drive it. Measure it. Compare it with specification. Document it.

That is how you move from "the car seems straight" to having genuine confidence that the repair beneath the paintwork has been completed properly.

Frequently Asked Questions About Car Frame Realignment

1. How accurate does car frame alignment need to be after a repair?

The repaired structure should fall within the manufacturer's specified dimensional tolerances for that particular vehicle. There isn't a universal acceptable difference—such as 2 mm, 5 mm or 10 mm—that applies to every car and every chassis measurement point.

Different datum points can have different specifications and tolerances. This is why professional frame alignment verification relies on vehicle-specific dimensional data rather than simply measuring both sides and deciding they look close enough.

If substantial structural straightening was carried out, ask whether the final frame measurements were confirmed against the appropriate OEM or manufacturer specifications.

2. Can a car frame become misaligned again after it has been straightened?

A correctly repaired structure shouldn't simply move out of alignment through ordinary driving. However, new collision damage, a severe impact with a kerb or pothole, damage to suspension or subframe components, or problems with a previous structural repair could result in new alignment concerns.

If a car initially drives correctly after repair but later develops pulling, unusual tyre wear, steering changes or altered panel fit, don't automatically assume the original frame realignment has moved. Have the new symptoms diagnosed to establish their actual cause.

3. Can a bent car frame be straightened more than once?

Potentially, but whether a structural section should be straightened again depends on the vehicle, the location and severity of the damage, its previous repair history and the relevant manufacturer repair procedure.

Repeatedly pulling or straightening a structural component isn't something that should be judged by appearance alone. Material properties and structural integrity matter as well as frame dimensions.

Where a previously repaired structural section has suffered another impact, a qualified repairer should establish whether the manufacturer permits another repair or whether the affected component or section requires replacement.

4. How long does professional chassis alignment checking take?

There is no single time that applies to every vehicle.

A straightforward chassis measurement may be relatively quick, whereas diagnosing a vehicle with previous structural repairs, dismantling components to access reference points, mounting it on specialist equipment and carrying out three-dimensional measurements can take considerably longer.

The time required can depend on:

• the type and construction of the vehicle;

• accessibility of the chassis measurement points;

• the measuring equipment being used;

• whether components require removal;

• the extent of previous collision damage; and

• whether measurement is being performed purely for inspection or as part of further structural repair.

The quality of the measurement and interpretation is more important than how quickly the check is completed.

5. How much does it cost to have a car frame alignment professionally checked?

The cost varies considerably according to the vehicle, location, repair facility, measuring system and depth of inspection required.

A geometry or wheel-alignment check is generally a different service from a comprehensive professional structural measurement, so make sure you're comparing like with like when requesting quotations.

If you're concerned about previous frame straightening, explain that you want the vehicle structure measured against the relevant manufacturer dimensions, rather than requesting only wheel tracking.

The repairer can then advise what level of inspection is appropriate and provide a quotation based on the vehicle.

6. Will an MOT test tell me whether my car frame was properly realigned?

You shouldn't treat an MOT pass as the equivalent of a detailed post-repair frame alignment verification.

An MOT concerns the vehicle's compliance with the applicable roadworthiness testing requirements at the time of the test. A specialist structural measurement has a different purpose: establishing the positions of defined chassis or body-shell points relative to the correct dimensional specifications.

Consequently, if you specifically want to know whether significant previous structural repair returned the chassis to the appropriate dimensions, ask for an appropriate structural inspection and measurement rather than relying solely on the vehicle's MOT status.

7. Can frame misalignment cause problems with new tyres even after wheel alignment?

Yes, although abnormal wear on new tyres can have numerous causes.

If the underlying suspension geometry, subframe position, suspension mounting locations or structural alignment remains incorrect, fitting new tyres doesn't address the cause. Similarly, carrying out a basic alignment may not resolve a problem caused by a bent component or displaced structural mounting point.

If newly fitted tyres begin developing abnormal wear soon after collision repairs, have the alignment and suspension investigated. If those checks don't explain the problem and the vehicle underwent significant structural work, further chassis measurement may be appropriate.

8. Does replacing a chassis rail mean the car needs frame alignment checking?

Following structural rail replacement, accurate positioning and dimensional verification can be particularly important.

A chassis or frame rail forms part of the vehicle structure, so its relationship with surrounding structural sections and designated measurement points needs to comply with the appropriate repair procedure and specifications.

Exactly what must be measured depends on the vehicle and repair.

Rather than assuming that fitting a new rail automatically makes everything straight, ask how its position was verified and whether relevant datum points and frame dimensions were checked after installation.

9. Should I get a frame alignment check before buying a previously accident-damaged car?

If you know a used vehicle has suffered significant structural collision damage, an independent inspection can provide information that appearance alone cannot.

This can be especially worthwhile when the repair history is incomplete, the vehicle has previously been classified for structural damage, or you notice suspicious tyre wear, unusual tracking, inconsistent body fit or evidence of structural repairs underneath.

Where possible, review:

• photographs of the original damage;

• repair invoices;

• structural measurement reports;

• wheel alignment records; and

• information showing which structural components were repaired or replaced.

For a car with substantial previous structural damage and little supporting documentation, an independent professional assessment can reduce the amount you're being asked to take on trust.

10. Can a properly realigned car be as safe and drive as well as it did before the accident?

The answer depends on considerably more than whether the frame dimensions are straight.

A properly completed collision repair should consider the structural repair procedure, dimensional alignment, suspension and steering components, wheel geometry and any other affected vehicle systems. The severity and location of the original damage also matter.

This is why the quality of a structural repair shouldn't be judged from cosmetic appearance or one successful alignment reading.

The stronger evidence is a properly documented repair in which affected structural sections were dealt with according to the applicable repair procedures, relevant chassis points were verified against manufacturer specifications, damaged mechanical components were addressed and the completed vehicle was appropriately inspected and tested.

In short, proper frame alignment is an essential part of a successful structural repair—but it isn't the only part that matters.