PROPER USAGE OF SPACER PLATE GASKETS IN OVERHAUL KIT

Model and Year: 1982-89 PASSENGER CAR AND TRUCK MODELS WITH 70OR4/4L60 TRANSMISSION

TO: ALL CHEVROLET DEALERS

This bulletin covers instructions for choosing the correct spacer plate gaskets from the transmission overhaul service package. Current information enclosed with the service package may be unclear when explaining which spacer plate gaskets are appropriate for use.

SERVICE PROCEDURE: (Figure 2)

Two sets of spacer plate gaskets are supplied with each transmission overhaul service kit. One set of gaskets is for use on model years 1982 through 1986, and the other set is for use on model years 1987-89.

The difference between the two sets of gaskets is the addition of holes in 1987 to accomodate an auxiliary valve body. Transmissions produced Start of Production or after the 1987 model year may or may not have an auxiliary valve body, but 1987-89 model years must use gaskets with holes for an auxiliary valve body even if an auxiliary valve body is not used.

If a 1987 or later transmission does not have an auxiliary valve body - the spacer plate covers up the unused holes in the spacer plate gaskets.

NOTICE: If the incorrect (1982-1986) gasket set is used on a 1987-89 model year transmission, with or without an auxiliary valve body, the third clutch exhaust passage will be blocked. This may cause slipping or flaring during a 3-2 shift, a delayed 3-2 downshift, or a burned 3-4 clutch.

SERVICE PARTS INFORMATION:

Model Year Part # Gasket Set Only Part # Overhaul Kit ---------- ---------------------- ------------------- 1982-1986 8642993 8649995 1987-1989 8657938 8649995

Parts are currently available from GMSPO.

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.