Century V6-173 2.8L VIN W FI (1987)
Torque Converter: Technical Service Bulletins
A/T - Torque Converter Condition Diagnosis
Bulletin
87-7440-19
Date
June, '89
Ref. No.
89-157-7440
Corp. Ref. No.
977112R
SUBJECT:
POSSIBLE INOPERATIVE TORQUE CONVERTER OR RELATED CONDITION
MODELS AFFECTED:
1985-87 CENTURYS, LESABRES, ELECTRAS AND RIVIERA-REATTA
BULLETIN COVERS
Information given for evaluation of the 245 mm torque converter, diagnosis and possible torque converter failure used in THM 440-T4/Hydra-matic
4T60 transaxles.
Causes for a possible torque converter condition are as follows:
-
A broken dampener plate rivet (inside the converter). These rivets hold the dampener assembly and the torque converter clutch apply plate
together.
-
Broken or loose spring tips. The springs are used on the dampener assembly to aid in torsional shock during TCC apply and reducing converter
clutch apply feel.
-
Converter pump vanes broken or loose.
-
Hydraulic leak due to worn or damaged seals.
-
Delamination of converter clutch apply plate fiber material.
The following is a list of symptoms that a vehicle may exhibit upon or during torque converter operation:
-
Shudder and/or vibration during torque converter clutch apply.
-
No upshift due to fiber material sticking valves and/or fiber material and metal particles in filter.
-
No drive and/or reverse.
-
Converter sprag inoperative (no torque multiplication).
-
Noisy converter bearings or excessive end play.
-
Pinging noise (constantly).
-
Vibration, out of balance, loose vanes (Noisy).
-
Vehicle may exhibit shudder or no TCC apply. Torque converter clutch lining delaminating due to coolant contamination from transmission
cooler.
-
Torque converter clutch crowd shudder condition. This condition is caused by a leak in the TCC circuit which could cause increased slippage and
wear away the fiber lining on the TCC apply plate. Possible causes for TCC circuit leakage include: worn turbine shaft seals, TCC solenoid
O-ring, valve body gaskets and auxiliary valve body gaskets, worn TCC accumulator piston pin or seal.
-
TCC apply shudder caused by converter dampener plate not parallel.
