ASE A4 Suspension and SteeringWheels and Tires Diagnosis and RepairMedium
A customer reports a 'clunking' noise coming from the front end of their vehicle when going over bumps or turning sharply at low speeds. The technician inspects the front suspension and finds no obvious issues with ball joints, tie rods, or control arm bushings. Upon jacking up the vehicle, the technician notices excessive play when grabbing the tire at 12 and 6 o'clock and rocking it. Which of the following is the MOST likely cause?
- AWorn upper or lower ball joints
- BLoose steering rack mounts
- CWorn inner tie rod ends
- DFailed strut mount bearings
Show answer & explanationAnswer & explanation
Correct answer: A. Worn upper or lower ball joints
Excessive play when rocking the wheel at 12 and 6 o'clock is a classic indicator of worn upper or lower ball joints. This movement primarily checks vertical play in the steering knuckle, controlled by the ball joints.
Why the other options are wrong
- B. Loose steering rack mounts would cause a clunk or play in the steering, but not typically manifest as excessive 12-6 o'clock wheel play.
- C. Worn inner tie rod ends would typically be detected with a 9 and 3 o'clock check and cause horizontal play.
- D. Failed strut mount bearings typically cause noise when turning the steering wheel and may affect ride height, but not directly cause 12-6 o'clock wheel play.
12-6 O'clock Wheel Play
Rocking the wheel at 12 and 6 o'clock checks for vertical play, primarily indicating worn upper or lower ball joints.
- Checks vertical movement of wheel
- Primary indicator of worn ball joints
- Requires vehicle to be jacked up for accurate check
Memory trick: Twelve-six for balls, nine-three for rods.