ASE A4 Suspension and SteeringSteering System Diagnosis and RepairMedium
A customer complains of a noticeable 'dead spot' in the steering, where the steering wheel can be turned a small amount without any immediate response from the road wheels. This condition is present even when the vehicle is stationary. Upon inspection, the technician finds no play in the tie rod ends or ball joints. What is the MOST likely cause?
- AAn air bubble in the power steering fluid.
- BA loose steering column mounting bracket.
- CA worn power steering pump.
- DExcessive internal play in the steering gear.
Show answer & explanationAnswer & explanation
Correct answer: D. Excessive internal play in the steering gear.
A 'dead spot' in the steering, where the wheel moves without a corresponding movement of the road wheels (even when stationary), strongly indicates excessive internal play within the steering gear itself. Since external linkage is ruled out, the issue is internal to the gear.
Why the other options are wrong
- A. An air bubble in the power steering fluid would primarily cause noise and reduced assist, not a mechanical 'dead spot' in steering wheel travel.
- B. A loose steering column mounting bracket would cause movement of the entire column and potentially clunking, but the input shaft would still directly turn the steering gear's input, not create a 'dead spot' within the gear's operation.
- C. A worn power steering pump would cause hard steering or noise, not a 'dead spot' or lack of response from wheel movement.
Steering Gear Internal Play
Internal play within a steering gear (rack and pinion or recirculating ball) refers to excessive clearance between its internal components, leading to a 'dead spot' in steering response.
- Manifests as a 'dead spot' or looseness in the steering wheel.
- Occurs before road wheels respond to steering input.
- Caused by wear in gears, bearings, or rack bushings.
- Reduces steering precision and control.
Memory trick: Internal Gear Gaps Generate Grievances.