For 1990-2009 cars

# UNIT REPAIR TRANS. THM 440T4 3-2 SHIFT CONTROL VALVE CHANGE

#### MODELS/YEARS: 1985 NINETY-EIGHT & 1984-85 CUTLASS CIERA

Hydra-matic is releasing eight new 1985 1/2 THM 440-T4 models to replace the 1985 models as indicated in the chart below. 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.

1985-85 1/2 MODEL IDENTIFICATION (ALL GM) ------------------------------------------ 1985 MODEL replaced by 1985 1/2 MODEL AC AF AY AM BC BR BU BV BX BW CP CM CW CN HT HJ

#### SERVICE PARTS INFORMATION

The 1985 1/2 model control valve assembly, spacer plate, and gaskets will not service the 1985 model. Until 19851/2 model part number listings are available, service replacement parts can be ordered through WDDGM by description (part name). Refer to Figure 1 for correct transaxle model identification information.

#### UNIT REPAIR INFORMATION

The current chassis service manual describes the 1985 models and will provide enough reference material to cover authorized dealer repairs for 19851/2 models. The exception is check ball locations. Refer to Figure 2 for control valve assembly and Figure 3 for channel plate check ball locations for the 19851/2 models.

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

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.