1990 - 1992 Corvette ZR-1: Service Bulletin: Engine Noise

Subject: ENGINE NOISE-INSTALL BUSHING 5.7L V8 (RPO LT5)
Model and Year: 1990-92 CORVETTE WITH 5.7L ENGINE (RPO LT5) AND MANUAL TRANSMISSION
Source: Chevrolet Service Bulletin
Bulletin Number: 92-230-6 - (06/15/1992)

Condition:

Some owners of 1990-92 Corvette ZR-1 may comment on a squeal noise that resembles a bearing noise. This noise may occur during clutch engagement from a standing stop. This noise can also occur during vehicle coast down with the clutch disengaged (clutch pedal depressed).

Cause:

This noise is due to the input shaft of the transmission contacting the crankshaft bushing. The noise usually occurs during clutch engagement from a standing stop or vehicle coast down because of the speed difference between the engine and the transmission input shaft.

Correction:

A revised crankshaft bushing is available to reduce the above condition. The revised bushing has grooves in the hole to reduce surface contact with the transmission input shaft.

Crankshaft Bushing P/N 10125896

Remove and install bushing per Service Manual.

Part Availability:

Parts are currently available from GMSPO.

Warranty Information:

Labor Operation: J1420 Use applicable labor time guide for labor hours.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.

1990 - 1992 Corvette ZR-1: Service Bulletin: Engine Noise - Install Bushing