ASE A4 Suspension and SteeringWheels and Tires Diagnosis and RepairMedium
A technician is inspecting a vehicle that exhibits a high-frequency vibration and a 'shimmy' in the steering wheel at speeds between 40-70 mph. The technician also notes some irregular tire wear on the front tires. Which of the following is the MOST appropriate next diagnostic step?
- ADiagnose the vehicle's shock absorbers and struts.
- BInspect the steering gear and tie rod ends for play.
- CCheck and adjust the front wheel alignment.
- DPerform a dynamic balance on all four wheel assemblies.
Show answer & explanationAnswer & explanation
Correct answer: D. Perform a dynamic balance on all four wheel assemblies.
A high-frequency vibration and shimmy in the steering wheel at specific speeds, combined with irregular tire wear, strongly suggests an imbalance in the front wheel assemblies. Dynamic balancing is the direct solution for this.
Why the other options are wrong
- A. Worn shocks/struts primarily affect ride quality, handling, and can cause cupping tire wear, but less commonly a distinct high-frequency shimmy.
- B. Play in steering components would cause looseness, wandering, or clunking, not typically a high-frequency shimmy at specific speeds.
- C. Alignment issues primarily cause tire wear and pulls, not typically a high-frequency shimmy.
Front Wheel Imbalance Symptoms & Correction
An imbalance in a front wheel assembly causes a high-frequency vibration or shimmy in the steering wheel, typically at specific speed ranges, and is corrected by dynamic wheel balancing.
- Vibration/shimmy in steering wheel
- Occurs at specific speed ranges (e.g., 40-70 mph)
- Corrected by dynamic wheel balancing
Memory trick: Wobbling wheel? Balance it, don't just align it!