A/T - THM 125C Harsh 1-2 Shift
Number 87-7-43 Date 9/87Subject: HARSH 1-2 SHIFT
1987 6000, SUNBIRD, GRAND AM, AND FIERO MODELS EQUIPPED WITH THM 125C (MD9)
BULLETIN COVERS:
Vehicles equipped with a 1987 THM 125C built between the dates of April 13, 1987 through April 21, 1987 (Julian Dates 103-112), may have a rolled or misassembled 1-2 accumulator piston seal, resulting in a possible harsh 1-2 shift. These 1987 THM 125C Transaxles (Julian Dates 103-112) have a new design accumulator piston (flat inner surface) and a soft synthetic rubber 1-2 accumulator piston seal that may be inadvertently misassembled.
Figure 1 - THM 125/125C Transaxle Identification Information:
DATE OF PRODUCTION CHANGE: (Figure 1)
New design accumulator piston (flat inner surface) and synthetic rubber accumulator piston seal on all 1987 THM 125C Transaxles built April 21, 1987 (Julian Date 103) through April 21, 1987 (Julian Date 112).
Figure 2 - Accumulator Piston Seals:
SERVICE ACTION: (Figure 2)
If a vehicle equipped with a 1987 THM 125C Transaxles built between Julian Dates 103-112 experiences a harsh 1-2 shift, examine the 1-2 accumulator piston and seal for damage or misassembly. If necessary, replace the Piston and Seal with the original design accumulator piston (raised rib) and P.T.F.E. seal.. These parts are not interchangeable.
SERVICE PARTS INFORMATION:
8631657 1-2 Accumulator Piston
8631895 1-2 Accumulator Piston Oil Seal Ring
SERVICE MANUAL REFERENCE:
Refer to the THM 125C Transaxle Unit Repair Section in the appropriate Service Manual.