A/T - TCC Engages In 2nd Gear
88buick06Bulletin: 88-7440-6
Date: April, '88
Ref. No.: 88-129-7440
Corp. Ref. No.: 877126
SUBJECT: TCC ENGAGES IN 2ND DUE TO MISSING OR MISPOSITIONED TCC SOLENOID SCREEN/SEAL
MODELS AFFECTED: ALL 1984-88 VEHICLES EQUIPPED WITH A THM 440-T4 (ME9) TRANSAXLE
FIGURE 1 - THM 440-T4:
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 O-Ring 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.
FIGURE 2 - THM 440-T4 TRANSAXLE IDENTIFICATION INFORMATION:
DATE OF PRODUCTION CHANGE (Figure 2)
NOTICE: All 1984 THM 440-T4 transaxles have the TCC solenoid screen in the valve body and do not use an O-Ring. 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 O-Ring 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, O-Ring (TCC Screen)
SERVICE MANUAL REFERENCE
Refer to the THM 440-T4 (ME9) Automatic Transaxle Unit Repair section for service information.