ASE A4 Suspension and SteeringSuspension System Diagnosis and RepairHard
A technician is diagnosing a vehicle with a multi-link rear suspension. The customer reports an intermittent 'wobble' or 'shimmy' sensation from the rear of the vehicle, particularly noticeable during highway driving or when changing lanes. Inspection reveals no loose wheel bearings or obviously bent wheels. Which of the following components is MOST likely contributing to this condition?
- ADamaged rear brake calipers
- BWorn rear shock absorbers
- CSeized rear sway bar bushings
- DExcessive play in the rear toe links
Show answer & explanationAnswer & explanation
Correct answer: D. Excessive play in the rear toe links
An intermittent 'wobble' or 'shimmy' from the rear, especially during highway speeds or lane changes, strongly suggests instability in the rear wheel's alignment. The toe links in a multi-link suspension are crucial for controlling toe angle and lateral wheel movement. Excessive play here would allow the rear wheels to steer themselves slightly, causing the described sensation.
Why the other options are wrong
- A. Damaged rear brake calipers would cause braking issues (pull, noise, vibration during braking), not an intermittent wobble during normal driving or lane changes.
- B. Worn shock absorbers primarily affect ride quality and body control (bounciness, excessive body roll), not typically an intermittent 'wobble' or 'shimmy' from the rear.
- C. Seized rear sway bar bushings would restrict sway bar movement, potentially leading to a harsher ride or increased body roll, but not a 'wobble' or 'shimmy' sensation.
Rear Toe Link Play
Excessive looseness or wear in the joint(s) or bushing(s) of the toe link(s) in a multi-link rear suspension.
- Causes rear wheel instability and 'self-steering'.
- Symptoms include wobble, shimmy, or vague handling at speed.
- Critical for maintaining correct rear toe angle.
Memory trick: When the rear 'WOBBLES' and 'SHIMMIES', the 'TOE' is probably dancing incorrectly.