GM Service Manual Online
For 1990-2009 cars only

FORCE BALANCER REPLACEMENT CAM GEAR TEETH ARE DAMAGED

FORCE BALANCER REPLACEMENT (WHEN CAM GEAR TEETH ARE DAMAGED)

VEHICLES AFFECTED: 1987 N CAR W/2.5L ENG. W/MAN. TRANS. AND 1988 A/N/P CARS W/2.5L ENGINE

When replacing camshaft timing gears, be aware that if one or more of the cam gear teeth have been damaged or broken off, the force balancer assembly must be replaced. It is NOT NECESSARY to replace the force balancer assembly in cases where the cam gear teeth are simply worn.

Cam gear tooth material can accumulate in the oil passages of the force balancer's counter-rotating shafts, restricting proper lubrication to the bearings of the balancer assembly. This condition may result in premature malfunction of the force balancer and/or engine.

The three components that comprise the force balancer assembly are as follows:

Cover Assembly, Oil Pump P/N 10038405 Housing Assembly, Force Balancer P/N 10042109-For 1987 "N" Car Only Housing Assembly, Force Balancer P/N 10101422-For 1988 Model Yr. Only GE-Rotor, Oil Pump P/N 10038402

Parts are currently available from GMSPO.

It is recommended that all three components be replaced when a cam gear has failed due to broken or sheared teeth.

Refer to Section 6A of the Service Manual for force balancer assembly and removal/installation details.

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.