A/T - Model Cross Reference & Component Changes
Number 85-7-23 Date 6/85Subject: THM 440-T4 SERVICE PARTS AND UNIT REPAIR INFORMATION
THM 440-T4 (ALL 1985 AND 1985 1/2 MODELS)
Hydra-matic is releasing eight new 1985 1/2 THM 440-T4 models to replace the 1985 models as indicated. 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
AC . . . . . . . . . .. . . . . . . AF
AY . . . . . . . . . . . . . . . . AM
BC . . . . . . . . . . . . . . . . BR
BU . . . . . . . . . . . . . . . . BV
BX . . . . . . . . . . . . . . . . BW
CP . . . . . . . . . . . . . . . . CM
CW . . . . . . . . . . . . . . . . CN
HT . . . . . . . . . . . . . . . . HJ
1985-1985 1/2 MODEL IDENTIFICATION
FIGURE 2 - TRANSAXLE 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.