GOVERNOR COVER/BEARING ASSY. RE-DESIGN

BEGINNING MID-MARCH, 1981, SOME THM 125 TRANSMISSIONS WERE BUILT WITH A NEW DESIGN GOVERNOR COVER BEARING IN PLACE OF THE PAST DESIGN THRUST WASHER. THIS BEARING WILL BE ONE OF TWO DESIGNS, (1) A THREE PIECE THRUST BEARING ASSEMBLY OR (2) A ONE PIECE BEARING. FOR SERVICE, ONLY THE THREE PIECE BEARING WILL BE USED. SEE FIGURE 1. A NEW DESIGN GOVERNOR COVER WAS ALSO PUT INTO PRODUCTION. THE HEIGHT OF THE GOVERNOR HUB WAS REDUCED TO ALLOW CLEARANCE FOR THE INCREASED THICKNESS OF THE BEARING. SEE FIGURE 2. THIS DESIGN CHANGE WAS MADE TO REDUCE FRICTION BETWEEN THE SPEEDOMETER GEAR AND GOVERNOR COVER DURING HIGH SPEED, LONG DISTANCE DRIVING. THIS CHANGE WILL ALSO CREATE A COMMON GOVERNOR COVER AND BEARING ASSEMBLY FOR THE THM 125, 125C, AND 325 TRANSMISSIONS. GOVERNOR COVER AND BEARING ASSEMBLY REDESIGN - CONTINUED SERVICE INFORMATION: 1.TO SERVICE THE GOVERNOR COVER AND BEARING ON ANY THM 125, 125C, OR 325 TRANSMISSION, ORDER SERVICE PACKAGE 8632985 WHICH WILL INCLUDE: A.) THE NEW DESIGN THREE PIECE BEARING ASSEMBLY. (ONLY THE THREE PIECE BEARING ASSEMBLY WILL BE USED FOR SERVICE.) B.) A GOVERNOR COVER "O" RING SEAL. C.) A NEW DESIGN 3 HOLE GOVERNOR COVER. SEE FIGURE 3. 2.DO NOT USE THE THREE PIECE BEARING ASSEMBLY OR THE ONE PIECE BEARING WITH THE PAST DESIGN GOVERNOR COVER. THIS COMBINATION WOULD NOT ALLOW PROPER CLEARANCE BETWEEN THE SPEEDOMETER DRIVE GEAR AND GOVERNOR COVER, CAUSING WEAR ON THE SPEEDOMETER GEAR. 3.DO NOT USE THE PAST DESIGN THRUST WASHER WITH THE NEW DESIGN GOVERNOR COVER. THIS COMBINATION WOULD HAVE EXCESS ENDPLAY BETWEEN THE SPEEDOMETER DRIVE GEAR AND THE GOVERNOR COVER, CAUSING ERRATIC SHIFTS AND SPEEDOMETER GEAR WEAR. GM PARTS DIVISION WILL NOTIFY DEALERS THROUGH SALES INFORMATION BULLETIN WHEN PARTS ARE AVAILABLE.

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.