Why Does My Car Pull to One Side?

Drift is not pull

Roads are built with a camber — a slight slope from the centre to the edge, so water runs off. A car driving in a normal lane is therefore sitting on a surface that tilts slightly towards the kerb, and gravity does what gravity does.

The result is that most cars drift gently towards the kerb side on a normal road, and that is not a fault. In countries that drive on the right, that means a gentle drift right; in countries that drive on the left, a gentle drift left.

How to separate the two:

• A drift is gentle and takes several seconds to become noticeable if you relax your grip.
• A pull is immediate and requires continuous steering pressure to counteract.
• Test on a flat surface — an empty car park, or the crown of a road where the camber reverses. If it tracks straight there and only wanders on normal roads, it is camber.
• Drive the same stretch in both directions. Camber drift changes side; a genuine pull stays on the same side of the car regardless of direction.

That last test is the most useful one on this page, and it costs nothing but a U-turn.

When it happens narrows it

Tyre pressure, first and free

Unequal pressure across an axle changes the rolling radius of the two tyres, and the car steers towards the softer side. It takes a surprisingly small difference to be noticeable.

• Check all four cold, before driving. Pressure rises as tyres warm, so a reading taken after a motorway run is not comparable with one taken cold.
• Use the figures on the door pillar or filler flap, not the number moulded into the tyre sidewall. The sidewall figure is the tyre's maximum, not your car's correct pressure — a distinction covered in the tyre pressure light guide.
• Front and rear are often different, and some cars specify different pressures for a loaded car.
• Set them all correctly and drive again before doing anything else. This alone resolves a meaningful share of pulls.

A tyre that keeps going soft is a slow puncture, and that is the thing to fix rather than the pull.

The tyre swap test

This is the test almost nobody does, and it identifies the most commonly misdiagnosed cause.

Tyres can pull on their own. A manufacturing characteristic called conicity means the tyre is very slightly conical rather than perfectly cylindrical, so it tries to roll in a curve. It can be present on a brand-new tyre and it is invisible — the tyre looks perfect, wears normally, and holds pressure.

The test:

1. Swap the two front tyres side to side — left to right, right to left.
2. Drive the same road.
3. If the pull swaps to the other side, it is a tyre. The fault moved because the tyre moved.
4. If the pull stays exactly where it was, it is not the tyres. Now alignment, brakes and suspension are worth investigating.

This matters financially. A car that pulls because of tyre conicity will still pull after a perfect alignment, because nothing was wrong with the alignment. The common story — "I had it aligned twice and it still pulls" — is very often this.

Other tyre-side causes worth checking while the wheels are off:

• Uneven wear across one tyre — more worn on one edge than the other, which both causes and results from alignment problems.
• Mismatched tyres across an axle: different brands, different tread patterns, or noticeably different tread depths.
• A damaged belt inside the tyre, often after a pothole. Sometimes visible as a bulge, sometimes not visible at all.

Alignment, and why it isn't always the answer

Alignment is the default diagnosis and it is frequently right — but it is worth understanding what is being adjusted, because that determines whether it can pull.

• Toe is whether the wheels point slightly inwards or outwards. Incorrect toe mostly causes rapid, feathered tyre wear rather than a pull.
• Camber is how far the top of the wheel leans in or out. Unequal camber across an axle is the classic alignment cause of a pull, because the car steers towards the side with more positive camber.
• Caster affects straight-line stability and self-centring. Unequal caster also pulls, and is often the cause when a car pulls but the tyres wear evenly.

Two practical points. First, ask for the before-and-after printout; it shows whether anything was actually out of specification, and by how much. Second, if the readings were within specification and the car still pulls, the alignment was not the cause and you have just paid to confirm that — which is useful information, but only if somebody then does the tyre swap test rather than aligning it again.

Alignment does go out, most often after hitting a pothole or a kerb hard enough to feel it. If the pull started on a specific day you remember, that is the likeliest explanation.

Pulls only when braking

A car that tracks straight until you touch the brakes, then veers, has a braking problem rather than a steering one. One side is producing more braking force than the other.

• A sticking caliper on one side, either seized pistons or seized slide pins.
• A collapsed flexible brake hose, which acts as a one-way valve — it lets pressure in but not out. The classic sign is a car that pulls one way under braking and has one wheel much hotter than the other afterwards.
• Contaminated pads on one side, from a leaking hub seal or spilled fluid.
• Uneven pad wear across the two sides.
• Worn suspension that only shows up under the weight transfer of braking.

After a drive, feel for heat near each front wheel — not touching the wheel or disc, just close enough to compare. One noticeably hotter side is a strong indicator, and it is the same mechanism behind braking judder.

A brake pull that is strong enough to be alarming is a stop-driving situation rather than a book-it-in one.

Pulls only when accelerating

If the car tracks straight at a steady speed and tugs at the wheel when you accelerate hard, the usual explanation is torque steer, and on many front-wheel-drive cars it is entirely normal.

It happens because the two driveshafts are usually different lengths, so they deliver torque slightly differently. Powerful front-wheel-drive cars do this by design, and there is nothing to fix.

What is not normal:

• Torque steer that suddenly got much worse, which points at a worn engine or gearbox mount letting the drivetrain move.
• A clunk with the pull, suggesting worn suspension bushings or a failing driveshaft joint.
• Pull under acceleration on a rear-wheel-drive car, which is not torque steer and warrants a look at the suspension.
• A pull that appears when lifting off rather than accelerating, which is more often worn bushings.

What to check, in order

1. Sudden strong pull? Stop and check for a flat tyre before anything else.
2. Drive the same road in both directions. If the pull swaps sides, it is road camber and not a fault.
3. Note when it happens — always, braking only, accelerating only.
4. Check all four tyre pressures cold against the door-pillar figures, set them correctly, and drive again.
5. Look at the tyres for uneven wear, bulges, mismatched brands and different tread depths.
6. Swap the two front tyres side to side and drive the same road. If the pull swaps, it is a tyre.
7. Braking only? Feel for one front wheel much hotter than the other after a drive.
8. Accelerating only, on a front-wheel-drive car? Probably torque steer, and probably normal.
9. Still pulling? Now get an alignment, and ask for the before-and-after printout.
10. Aligned and still pulling? Go back to the swap test if it was skipped — that is the usual missing step.