ASE A4 Suspension and SteeringSuspension System Diagnosis and RepairEasy
A technician is inspecting a vehicle with a double wishbone front suspension. The customer reports a clunking noise when turning at low speeds and a loose steering feel. Upon inspection, the technician notices excessive play in the upper control arm mount points. Which of the following is the MOST likely cause of these symptoms?
- AIncorrect wheel alignment
- BDamaged shock absorber
- CWorn lower ball joint
- DWorn upper control arm bushings
Show answer & explanationAnswer & explanation
Correct answer: D. Worn upper control arm bushings
Excessive play in control arm mount points directly indicates worn bushings. Worn bushings in a double wishbone suspension will lead to instability and noise, especially during steering maneuvers.
Why the other options are wrong
- A. Incorrect wheel alignment causes tire wear and pulling, but not directly clunking from control arm mount play.
- B. A damaged shock absorber primarily affects ride comfort and damping, not typically causing play or clunking in control arm mounts.
- C. While a worn lower ball joint can cause clunking and loose steering, the play was noted specifically in the upper control arm mount points.
Control Arm Bushing Wear
Rubber or polyurethane components that cushion the pivot points of control arms, absorbing road shock and allowing controlled movement. When worn, they can cause noise, play, and poor handling.
- Connects control arm to frame/subframe
- Dampens vibrations and allows articulation
- Wear leads to clunking, squeaking, loose steering
Memory trick: Wishbone bushings are the silent links, when worn, they clunk and make steering sink.