Quick answer
If the lower arm has excessive play, worn bushes, a bad ball joint or structural damage, it may fail the MOT.
Minor wear may be advisory, but unsafe movement often results in failure.
Common MOT failure reasons
Worn bushes
Rubber bushes split or moving excessively.
Ball joint play
Movement in the lower arm joint.
Bent arm
Impact damage from potholes or kerbs.
Corrosion
Serious rust weakening the component.
Loose fixing bolts
Insecure mountings or hardware.
Unsafe condition
Any defect affecting suspension safety.
Signs a lower arm may be worn
- !Knocking over bumps.
- !Uneven tyre wear.
- !Poor alignment or pulling.
- !Steering vagueness.
- !Visible split bushes.
Should you repair before MOT?
Yes. Lower arm faults can affect tyre wear, steering stability and braking behaviour. Repairing beforehand can avoid failure and improve safety.
Many vehicles need the complete arm replaced rather than bushes alone.
Related MOT guides
Frequently asked questions
Will worn bushes fail MOT?
If movement is excessive or unsafe, yes.
Can a bent lower arm fail?
Yes, damage affecting alignment or strength can fail.
Does it affect tyre wear?
Yes, suspension geometry can be affected.
Are lower arms expensive?
Costs vary by vehicle and labour time.