* This bulletin supercedes Produce Service Bulletin 83-7-158, all copies of which should be destroyed.
When servicing the oil pump rotor and slide on a THM 125/125C transaxle, refer to the appropriate Service Manual, which describes the following procedure:
Use a micrometer to measure the original pump rotor and/or slide thickness. Refer to Figure 1. Take measurement on a f lat, undamaged surface.
Use the original part measurement to select the proper service package from the following charts:
1980-1981 THM 125 (Order rotor and slide separately)
Rotor (mm) Part Number Slide (mm) Part Number
17.943-17.955 8653961 17.955-17.967 8631800 17.956-17.968 8653962 17.968-17.980 8631801
17.969-17.981 8653963 17.981-17.993 8631802 17.982-17.994 8653964 17.994-18.006 8631803 17.995-18.008 8653965 18.007-18.020 8631804
1982-1986 THM 125C (Order rotor and slide as complete package)
Rotor (mm) Service Package Number
17.943-17.956 8652903 17.956-17.969 8652904 17.969-17.982 8652905 17.917-17.930 8652906 17.930-17.943 8652907
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.