This bulletin covers new 1-2 and reverse band assemblies that do not require selective band apply pins.(Figures 1 and 2) A new manufacturing process machines the area where the case anchor pins contact the band. With this new process, all the 1-2 bands are the same size and all the reverse bands are the same size. With the bands all the same size, selective band apply pins are not required. NOW, THERE IS NO NEED TO MEASURE FOR SELECTIVE BAND APPLY PINS FOR THE ENTIRE NORMAL SERVICE LIFE OF THE BAND.
Do not measure for selective band apply pins - this will be removed from the labor time allowance for all applicable 1991 labor K-codes. If replacing a 1984 through 1991 model year transaxle 1-2 or reverse band, it is not necessary to measure for selective band apply pin(s), provided that the band service package contains an instruction sheet about the non-selective band apply pin band.
Beginning July 2,1990 (Julian Date 183), all 1991 HYDRA-MATIC 4T60 transaxles were built with the new 1 - 2 and reverse band assemblies.
The new bands will replace the previous bands.
Part Model Model Number Description Year Usage ------- ---------------------- ------- ----- 8675986 Package - Reverse Band Asm. 1984-91 All - Reverse Band Assembly - Instruction Sheet
8656543 Pin - Reverse Band Apply 1984-91 All
8675987 Package - 1-2 Band Asm. 1984-91 All - 1-2 Band Assembly - Instruction Sheet
8656540 Pin - 1-2 Band Apply 1984-91 All
Parts are currently available from GMSPO.
Refer to the appropriate Service Manual for proper disassembly and assembly procedures. The 1991 Service Manual shows the procedure to measure the 1-2 and reverse band apply pins and should be disregarded.
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.