ASE A4 Suspension and SteeringSteering System Diagnosis and RepairMedium
A vehicle exhibits a loud 'clunk' or 'thump' noise from the front end, particularly when turning the steering wheel sharply or driving over bumps. The technician inspects the steering linkage and finds no excessive play in the tie rod ends, pitman arm, or idler arm. However, when the steering wheel is turned, a noticeable movement is observed between the steering column shaft and the steering gear input shaft. What is the MOST likely cause of this noise?
- AA faulty steering dampener.
- BA worn or loose steering column U-joint.
- CA worn power steering pump.
- DAn out-of-balance wheel.
Show answer & explanationAnswer & explanation
Correct answer: B. A worn or loose steering column U-joint.
A 'clunk' or 'thump' noise during turns or over bumps, coupled with visible movement between the steering column shaft and the steering gear input shaft, strongly indicates a worn or loose U-joint in the steering column. This joint connects the column to the steering gear and can develop play over time.
Why the other options are wrong
- A. A faulty steering dampener would affect steering stability and feel, but not generally cause a 'clunk' from play between the steering column and gear.
- C. A worn power steering pump typically causes groaning and increased steering effort, not clunking from play.
- D. An out-of-balance wheel would cause vibration at speed, not a clunking noise related to steering input or bumps.
Steering Column U-Joint Noise
A worn or loose universal joint (U-joint) in the steering column can cause distinct clunking or popping noises, particularly during steering input or when suspension components move.
- Connects steering column to steering gear.
- Allows for angle changes between components.
- Failure manifests as clunking or popping noises.
- Can also lead to excessive steering play or binding.
Memory trick: Joint Jiggles Generate Jumps.