NEW DESIGN LO AND REVERSE ASSY 125 TRANSMISSION
Subject: NEW DESIGN LO AND REVERSE CLUTCH ASSEMBLY - 1982 THM 125/125C
Beginning mid-July, 1981, some 1982 THM 125/125C transmission models were assembled with a new design lo and reverse clutch assembly. See Figure 1. This design change will produce a more desirable neutral to reverse garage shift feel.
This new design consists of the following (refer to Figure 2):
1. A modified lo and reverse piston, eliminating the need for an apply ring.
2. A waved steel clutch plate next to the lo and reverse piston, eliminating one (1) flat steel clutch plate.
3) A smaller lo and reverse clutch housing feed orifice.
SERVICE INFORMATION
1. The following chart contains the necessary service package numbers for all THM 125/125C transmissions.
LO AND REVERSE CLUTCH ASSEMBLY SERVICE PACKAGE NUMBERS
Past Design New Design Part Name 1980-1981 1982 ---------------------------------- ----------- ---------- Housing and bushing lo and reverse clutch 8637514 8643921
*Housing and bushing lo and reverse clutch (with piston and waved plate) 8643921
*Lo and reverse clutch piston and apply ring assembly 8631929
In and reverse clutch piston assembly (with waved plate 8637574) 8643922
Steel clutch plate 8631079
Waved clutch plate 8637574
* A waved clutch plate must be used with the new design one (1) piece piston.
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.
