4-SPEED MANUAL OVERDRIVE TRANS LUBE RECOMMENDATION

MODELS: 1981 GMC PICKUPS WITH MANUAL TRANSMISSIONS

On page 5-9 under Manual Transmission, SAE 80GL-5 or SAE 80W-90 GL gear lube is recommended when additional lube is needed to properly fill the transmission case.

This is the correct lubricant recommendation for all manual transmissions except for the 4-speed manual overdrive transmission (RPO MM7). This transmission uses only Dexron II automatic transmission fluid. Add Dexron II automatic transmission fluid ONLY to the 4-speed manual overdrive transmission case, if needed.

See Maintenance Schedule folder for additional information and fluid check intervals.

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.