ASE A4 Suspension and SteeringSuspension System Diagnosis and RepairMedium
A vehicle with multi-link rear suspension exhibits excessive tire wear on the outer shoulder of the rear tires and a noticeable 'loose' feeling in the rear end during cornering. This condition is present even after a recent alignment. The technician suspects worn bushings. Which of the following multi-link components, when worn, would MOST directly cause these symptoms?
- AWorn trailing arm bushings
- BWorn toe link bushings
- CWorn lower control arm bushings
- DWorn upper control arm bushings
Show answer & explanationAnswer & explanation
Correct answer: B. Worn toe link bushings
The toe link in a multi-link suspension is critical for controlling the toe angle. Worn toe link bushings allow excessive movement, leading to dynamic changes in toe, which causes outer tire wear (due to toe-out under load) and a 'loose' or unstable feeling in the rear end, especially during cornering.
Why the other options are wrong
- A. Worn trailing arm bushings primarily affect fore/aft wheel movement and could cause clunking or wheel hop, but less directly outer tire wear or cornering instability.
- C. Worn lower control arm bushings would also affect camber and potentially cause clunking, but again, dynamic toe changes are more characteristic of toe link issues.
- D. Worn upper control arm bushings would primarily affect camber and could lead to uneven tire wear (inner or outer depending on camber change), but toe instability is more directly linked to toe links.
Multi-Link Toe Link
In a multi-link suspension, the toe link is a crucial component that controls the toe angle of the wheel. Wear in its bushings leads to dynamic toe changes and instability.
- Connects the knuckle to the subframe/chassis
- Adjustable for toe alignment
- Worn bushings cause unstable handling and uneven tire wear
Memory trick: Toe Link's loose, the rear gets wild, like a toddler unrestrained.