Something changed after hitting a pothole
The car drove normally before the impact and does not now.
Direct causeA vertical and rearward impact load transmitted through the tyre into components designed for a fraction of it.
Physical realityThe load runs tyre → rim → hub → control arm and bushes → strut → subframe, and it stops at the weakest link in that chain. That is rarely the part you can see. A rim usually buckles on the inner lip, which faces away from you when the wheel is on the car.
Safety riskMedium to high. A new pull, a new vibration or a changed steering feel after an impact should be inspected before the next long drive, because a damaged sidewall fails without warning at speed.
Required fixInspect the whole load path on a hoist, then a four-wheel alignment with the before and after readings kept. Alignment on its own adjusts around a bent component and hides it in the numbers.
What usually causes it
- Buckled rim — commonly on the inner lip; often shows first as a slow leak or a vibration rather than anything visible.
- Tyre sidewall bulge — internal cord damage. The tyre must be replaced — a sidewall cannot be repaired.
- Bent track rod or tie rod end — puts toe out of specification and pulls the steering wheel off centre.
- Damaged control arm or bush — changes camber and caster, and often announces itself as a knock over bumps a few weeks later.
Diagnostic verification criteria
How a workshop separates these causes rather than replacing parts in sequence.
- Primary indicator: A steering wheel that now sits off centre on a road you know to be straight means the geometry has moved. That is a measurement, not an opinion, and it separates an impact that did damage from one that did not.
- Tolerance limit: A sidewall bulge of any size condemns the tyre. There is no acceptable dimension — the cords are already broken.
- Secondary failure risk: A buckled rim that is merely balanced out keeps flexing the tyre bead and returns as a slow puncture, usually somewhere less convenient than a workshop.
RM Steering and Suspension inspects impact damage in Brackenfell, Cape Town — wheels, steering and geometry together.
Request an impact inspection