TCC ENGAGES IN 2ND CHECK TCC SCREEN SEAL P/N

MODELS AFFECTED: ALL 1984-88 VEHICLES EQUIPPED WITH A THM 440-T4 (ME9) TRANSAXLE

BULLETIN COVERS: (Figure 1) --------------- The following conditions may occur on some of the subject vehicles if the Torque Converter Clutch (TCC) solenoid screen (Item 33) and/or ORing seal (Item 68) is missing from the spacer plate or mispositioned in the spacer plate:

- TCC applies during 1-2 shift.

- TCC applies in 2nd gear during acceleration, then releases at steady throttle in 2nd gear.

- TCC appears not to apply in 3rd gear because it already applied in 2nd gear.

- TCC applies with wiring harness disconnected from transaxle.

DATE OF PRODUCTION CHANGE (Figure 2)

NOTICE: All 1984 TM 440-T4 transaxles have the TCC solenoid screen in the valve body and do not use an ORing. The conditions listed above do not apply to these early transaxles, which are listed below:

Model Year/ Built Before Model Julian Date

1985 BA 192 1985 BC 198 1985 BS 224 1985 BN 194 1985 CW 192 1985 OB 192 1985 OY 192

Refer to Buick Service Bulletin 85-7440-7 for early model TCC solenoid screen service information.

SERVICE ACTION

When the valve body is removed from a THM 440-T4 for any reason, make sure the TCC solenoid screen and/or ORing is not missing or mispositioned. Sometimes the screen may be mispositioned due to wear or breakage of the plastic tabs that hold the screen in the spacer plate. If the screen or seal is missing, worn or damaged, replace with the service part listed below.

SERVICE PARTS INFORMATION

Part No Description ------- ----------- 8658060 Screen Assembly, TCC Solenoid 8658109 Seal, ORing (TCC Screen)

SERVICE MANUAL REFERENCE

Refer to the THM 440-T4 (ME9) Automatic Transaxle Unit Repair section for service information.

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.