A/T - Service Parts & Unit Repair Information

85-86

7A

MAY, 1985

Subject: THM 440-T4 SERVICE PARTS AND UNIT REPAIR INFORMATION

Model and Year: ALL 1985 AND 1985 1/2 MODEL

TO: ALL CHEVROLET DEALERS

Hydra-matic is releasing two (2) new 1985 1/2 THM 440-T4 models to replace the 1985 models as indicated in Figure 1. The 1985 1/2 models have a redesigned control valve assembly with a new 3-2 line control valve that makes the 3-2 downshift more responsive to throttle position. The oil passages in the control valve assembly, channel plate, spacer plate, and gaskets have also changed.


1985 MODEL...replaced by...1985 1/2 MODEL CP.......................CM CW.......................CN

FIGURE 1 1985-1985 1/2 MODEL IDENTIFICATION

FIGURE 2TRANSAXLE MODEL IDENTIFICATION NAMEPLATE INFORMATION:

Service Parts Information

The 1985 1/2 model control valve assembly, spacer plate, and gaskets will not service the 1985 model. Until 1985 1/2 model part number listings are available, service replace parts can be ordered through GMWDD by description (part name). Refer to Figure 2 for correct transaxle model identification information.

FIGURE 3 CHECK BALL LOCATIONS - CONTROL VALVE ASSEMBLY:

FIGURE 4 CHECK BALL LOCATIONS - CHANNEL PLATE:

Unit Repair Information

The current Service Information Manual describes the 1985 models and will provide enough reference material to cover authorized dealer repairs for 1985 1/2 models. The exception is check ball locations. Refer to Figure 3 for control valve assembly and Figure 4 for channel plate check ball locations for the 1985 1/2 models.

Unit repair information for 1985 1/2 models will be provided in a bulletin.