VALVE ROCKER ARM BOLT FAILURE (INSPECT/REPLACE BOLTS)

SUBJECT: VALVE ROCKER ARM BOLT FAILURE (REPLACE BOLTS)

VEHICLES AFFECTED: 1991 C/K,, R/V, G,P, C5H, C6H, C7H WITH 6.OL, 7.OL AND 7.4L ENGINES

CONDITION:

--------- Owners of some 1991 trucks with 6.OL, 7.OL, or 7.4L engines may experience a valve rocker arm bolt failure.

CAUSE:

----- One manufacturer of this rocker arm bolt had forming cracks at shoulder of the bolt.

CORRECTION:

---------- Although the frequency of this type of failure will be very low, GM is suggesting that if this occurs, all bolts identified as shown in the illustration be replaced with P/N #10114123.

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.