HARSH 3-4 SHIFT (INSPECT VALVE BODY 4TH CLUTCH. Buick Park Avenue 1997

THIS IS A MONTHLY SERVICE NEWSLETTER ARTICLE. THIS IS NOT INTENDED TO BE A PUBLISHED BULLETIN

SUBJECT: HARSH 3-4 SHIFT (INSPECT VALVE BODY, 4TH CLUTCH, AND 3-4 ACCUMULATOR HOUSING)

MODELS: 1997-98 BUICK PARK AVENUE/ULTRA 1998 BUICK LESABRE 1997-98 BUICK RIVIERA 1998 BUICK REGAL WITH 4T65E TRANSAXLE

CONDITION:

HARSH 3-4 UPSHIFT.

CORRECTION:

THE MOST COMMON CAUSE OF THIS CONCERN IS DUE TO A SCORED 3-4 ACCUMULATOR VALVE (ILL. #341) AND/OR ACCUMULATOR VALVE BORE WHICH REQUIRES A VALVE BODY REPLACEMENT. HOWEVER, IF INSPECTION OF THE VALVE BODY REVEALS NO CONCERN, THE 4TH CLUTCH PISTON, SEAL AND 3-4 ACCUMULATOR HOUSING SHOULD BE INSPECTED. ADDITIONALLY, THE OPERATION OF THE TORQUE CONVERTER CLUTCH PWM SOLENOID SHOULD BE CHECKED, AS THIS MAY CAUSE A HARSH TCC APPLY AT THE SAME TIME AS THE 3-4 UPSHIFT, THUS CONFUSING DIAGNOSTICS.

ALL SHIFT ADAPTS SHOULD BE CLEARED FROM THE PCM AFTER ANY REPAIR AND THE VEHICLE TEST DRIVEN TO VERIFY REPAIRS.

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