THM 125/125C TRANS.REVISIONS P/N CHANGES AND TRANS. IDENT.. Buick Skyhawk 1984

For 1990-2009 cars

# THM 125/125C TRANS.REVISIONS P/N CHANGES AND TRANS. IDENT.

#### MODELS AFFECTED: LATE 1984 MODEL THM 125/125C TRANSAXLES AND ALL 1985 MODEL THM 125/125C TRANSAXLES

Starting in May, 1984, a new oil pump drive shaft and spacer assembly, pump shaft bearing and seal assembly and control valve and pump assembly went into production on all THM 125/125C transaxles built in the United States.

The new parts provide easier and improved assembly procedures.

The former parts (Fig. 1) are not interchangeable with the new parts (Fig. 2) listed above for the following reasons.

1. The new oil pump drive shaft and spacer assembly has a thimer spacer and a longer bearing journal diameter to accomodate the new pump shaft bearing and seal assembly (Fig. 2).

2. The new pump shaft bearing and seal assembly was also made longer in length to accommodate the seal as part of the bearing assembly (Fig. 2).

3. The new control valve and pmp assemblies were changed to accommodate the new oil pump drive shaft and roller pump shaft bearing and seal assemblies.

Refer to Chart 1 for the serial number breakpoints. If the transaxle being serviced has a serial number smaller than the number shown in Chart 1, it will have the former parts (refer to the 1984 parts list book). If the number is the same or larger, it will have the new parts (refer to Charts 2 and 3 for new part numbers and model applications).

#### Important: All THM 125C transaxles built in Cansda will have these new parts beginning start of production 1985. Some model THM 125C transaxles built in Canada are also built in the United States and can be distinguished from each other by their nameplates. The U.S. models have serial numbers (Fig. 3) and Canadian models have Julian Dates (Fig. 4).

#### NOTE: This change affects only the transaxles built in the United States.

#### CHART 1

SERIAL NUMBER STARTING WITH NEW OIL PUMP SHAFT AND SPACER ASSEMBLY, PUMP SHAFT BEARING AND SEAL ASSEMBLY, AND CONTROL VALVE AND PUMP ASSEMBLY

#### MODEL SERIAL NUMBER ------ -------------

CA 2921 CB 240974 CC 1787 CE 83327 CT 4840 PD 2762 PE 70659 PF 34901 PG 69397 PJ 9033 PW 90895

#### CHART 2

PART NAME PART NUMBER MODEL --------- ------------ ----- OIL PUMP DRIVE SHAFT AND SPACER ASSEMBLY 8643764 ALL

PUMP SHAFT BEARING, AND SEAL ASSEMBLY 8643762 ALL

#### CHART 3

NEW CONTROL VALVE BODY ASSEMBLIES STARTING WITH SERIAL NUMBERS SHOWN IN CHART NUMBER 1

PART NUMBER MODEL ------------ ----- 8652251 CE 8652255 CA, CB 8652263 CC, CT 8652254 PE, PG 8652265 PD 8652268 PF 8652267 PJ 8652260 PW

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.