Brakes - Steering Wheel Shimmy During Braking: Overview
90nissan05Classification: Section
BR90-004 Brake System
Reference:
SERVICE ADVISORY NTB90-088
Models:
1990 300ZX, 300ZX Turbo Date:
September 27, 1990
1990 300ZX STEERING WHEEL SHIMMY DURING BRAKING
APPLIED MODEL: 1990 300ZX 1990 300ZX Turbo
SERVICE INFORMATION
On some 300ZX vehicles, customers may complain of a "brake-shimmy", which is defined as a low frequency vibration that causes the steering wheel to rotate very slightly from side to side.
This incident is caused by excessive variation in the thickness of the front brake rotors resulting from lateral run-out of the front brake rotors. Consequently, when the brakes are applied, the front braking torque varies slighty, causing a vibration in the steering wheel, floor pan, seats or body.
The long term effectiveness of the repair procedure below depends on the reduction of rotor run-out and thickness to levels at or below tbe service limits. Run-out service limit: 0.07 mm (0.0028 in)
Thickness variation service limit: 0.01 mm (0.0004)
Failure to reduce run-out and thickness variation will result in come-back incidents.