Subject: New 3-4 Clutch Apply Package
FIGURE 13:
FIGURE 13A:
FIGURE 14:
CHANGE TO ASSEMBLY COMPONENTS:
NOTICE: Certain transmissions ("A" Models, Figure 14) will have two steel plates stacked together in two places (one in the middle) to provide the same stack-up as a six plate clutch assembly and to draw heat away from the fiber plates. When assembling the 3-4 clutch, refer to Figures 13, 13A and 14 for proper assembly.
^ New 3-4 clutch apply plate "stepped" replacing a "flat" apply plate (Figure 13)
^ Input housing and shaft assembly revised with longer housing splines for using the new 3-4 clutch apply plate
^ New input internal gear with longer splines on outside diameter
^ Eliminate usage of longer 3-4 clutch apply ring (now only using short 3-4 clutch apply ring on all models)
^ New 3-4 backing plates, (material and thickness)
^ New internal retaining ring (thinner) and end configuration changed for identification
SERVICE ACTION:
The new 3-4 clutch apply plate or the new input housing and shaft assembly cannot be used on transmissions built prior to February 9, 1987 (Julian Date 040).
SERVICE PARTS INFORMATION:
Part Number Description
8642173 Plate, 3-4 Clutch
8667423 3-4 Clutch Apply Plate
8667661 Input Housing & Shaft Assembly (621) (used with 245 mm converter)
8667659 Input Housing & Shaft Assembly (621) (used with 298 mm converter)
8667660 Input Housing & Shaft Assembly (621) (used with 298 mm converter
MHM model only)
8663636 Internal Retaining Ring
8663639 Input Internal Gear
FIGURE 15:
3-4 Clutch Backing Plate Selection Procedure (Figure 15)
1. With the input housing and shaft assembly fully assembled, use a feeler gage to measure for correct backing plate travel (Figure 15).
2. Select the proper backing plate to obtain the specified travel (Figure 15).
SERVICE MANUAL REFERENCE:
1987 Service Manuals do not contain the information in this bulletin. Use the procedures and information provided in this bulletin in addition to your Service Manual to service a transmission built after this change.