A client complains that their vehicle pulls to the right, even after a recent alignment. The technician performs a road test and confirms the pull. The alignment machine shows all angles within specification. What is the MOST likely non-alignment related cause for this vehicle pull?
- AExcessive positive caster on the left front wheel.
- BA misaligned subframe.
- CWorn lower control arm bushings on the right front.
- DIncorrect tire pressure on the left front tire.
Show answer & explanationAnswer & explanation
Correct answer: D. Incorrect tire pressure on the left front tire.
If all alignment angles are within specification, non-alignment related issues become the primary suspects for a vehicle pull. Uneven tire pressure, especially a low tire on one side, can significantly cause a vehicle to pull to the side with the lower pressure (or away from the higher pressure). In this case, if the left front tire has incorrect (likely low) pressure, it would cause a pull to the left, but if the right front tire had low pressure, it would cause a pull to the right.
Why the other options are wrong
- A. Excessive positive caster on the left front would cause a pull to the left, and if all angles are within spec, this shouldn't be the case.
- B. A misaligned subframe would cause alignment angles to be out of specification, which is contrary to the premise of the question.
- C. Worn suspension components usually cause alignment angles to be out of spec or lead to dynamic changes that the alignment machine might not catch, but incorrect tire pressure is a simpler, more common cause.
Non-Alignment Vehicle Pull Causes
If alignment angles are within specification but a vehicle still pulls, common causes include uneven tire pressure, worn suspension components, brake drag, or radial tire pull.
- Always check tire pressure first.
- Inspect for worn parts.
- Consider brake issues.
Memory trick: If alignment is fine, check the tires or the parts that bind.