ASE A4 Suspension and SteeringSuspension System Diagnosis and RepairEasy
A technician is diagnosing a vehicle with a double wishbone front suspension. The customer reports a 'creaking' noise heard at low speeds, particularly when turning or going over small bumps. Upon inspection, the technician notices a torn boot on the upper ball joint and feels slight play when prying the wheel up and down. Which of the following is the MOST likely cause of the noise and play?
- AWorn sway bar end links
- BLoose control arm bushings
- CWorn upper ball joint
- DFailed shock absorber
Show answer & explanationAnswer & explanation
Correct answer: C. Worn upper ball joint
A torn boot on a ball joint allows dirt and moisture to enter, leading to premature wear and lubrication loss. The 'creaking' noise and play when prying the wheel are classic symptoms of a worn ball joint, which is a critical pivoting point in the suspension.
Why the other options are wrong
- A. Worn sway bar end links typically cause a 'clunking' noise, not usually a 'creaking', and less likely to cause wheel play.
- B. Loose control arm bushings can cause noise and some play, but a torn boot and direct play in a ball joint are more indicative of ball joint failure.
- D. A failed shock absorber would primarily affect ride quality and damping, not typically cause a creaking noise or wheel play.
Worn Ball Joint Symptoms
Symptoms of a worn ball joint include creaking or popping noises during turns or over bumps, and excessive play when inspecting the wheel.
- Torn boot allows contamination and lubricant loss.
- Causes friction and excessive movement.
- Can lead to steering instability and uneven tire wear.
Memory trick: Noisy joints make the ride rough, check for play and torn cuffs.