TRANSMISSION APPLICATIONS: SUBJECT: ------------------------- ------- 1988 THM 125C(MD9) SERVICE AND PARTS INFORMATION ON A NEW FINAL DRIVE ASSEMBLY
TRANSMISSION MODELS: VEHICLE APPLICATIONS: ------------------- -------------------- ALL 1988 'A,J,L,N,T' WITH 125C TRANSMISSION
New style Final Drive Assemblies (678) for some 1988 vehicles equipped with a THM 125C transaxle having 3.33, 3.06, 2.84 final drive ratios. These new final drive assemblies have larger differential side gears (687) and larger differential pinion gears and a smaller diameter cross shaft which is black in color. The new style Final Drive Assemblies are going into production due to the increased use of higher torque engine calibrations.
DATE OF PRODUCTION CHANGE: (Refer to Figure 1)
May 3, 1988 (Julian Date 124) for all THM 125C transaxles using a 3.33 ratio final drive assembly, May 23, 1988 (Julian Date 144) for all models using the 3.06 ratio final drive assembly and S.O.P. 1989 for some models using the new style 2.84 ratio final drive assembly.
When servicing a 1988 THM 125C transaxle use the parts listed in the Service Parts information section below. Do not attempt to mix new style final drive components with previous final drive components that look similar or the following conditions will occur:
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.