POWER STEERING SHUDDER/GROAN INSTALL P/S COOLER & HOSE

SUBJECT: POWER STEERING SHUDDER/GROAN (INSTALL POWER STEERING COOLER AND TUNED HOSE ASSEMBLIES)

VEHICLES AFFECTED: 1988-90 CHEVROLET Y-CAR WITH.5.7L

CONDITION:

---------- Some 1988-90 Y-cars with either L98 or LT5 engines and assembled prior to VIN breakpoint L5115181 or L5802113 respectively, may exhibit a slight power steering related shudder/groan condition. This condition is typically apparent during either static or low speed turning maneuvers and may be perceived by the vehicle operator as a vibration felt in the vehicles steering wheel.

CAUSE:

------ A combination of power steering pump pressure pulses and engine firing frequency transmitted through the body structure.

CORRECTION:

------------ Utilizing model year/engine - suspension RPO matrix shown below, determine applicable steps to be performed on the vehicle being serviced. When determining corrective action for 1990 vehicles, attention must be paid to VIN breakpoints.

ENGINE/SUSPENSION RPO 1988 1989 1990 --------------------- ------ ------ ---------

L98/FE7 A and B A and B A*,B and E@ (Finned Power Steering Cooler)

L98/FE1 B and C B and C B,C* and E@ (Loop Power Steering Cooler)

LT5/ZRl -- -- D# and E+

* SOP thru 115181 @ 113000 thru 115181 + 801883 thru 802113 # SOP thru 802113

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.