A/T - TCC Busyness Caused By Early 3-4 Shift
88buick03Bulletin: 86-7440-8A
Date: Feb. '88
Ref. No.: 86-215A-7440
Corp. Ref. No.: 677135R
SUBJECT: TORQUE CONVERTER CLUTCH (TCC) BUSINESS CAUSED BY EARLY 3-4 SHIFT
MODELS AFFECTED: 1986 LESABRES AND ELECTRAS EQUIPPED WITH 3.0L AND 3.8L V-6 ENGINES AND THM 440-T4 (ME9) MODELS 6BAH, 6BBH, 6BDH, 6BHH, 6BLH, 6BMH
NOTICE: This bulletin is revised to include 6BHH model transaxle which was omitted in the original 86-7440-8 bulletin. Bulletin 86-7440-8 should be discarded.
BULLETIN COVERS
Torque converter clutch (TCC) busyness caused by an early 3-4 shift in 1986 "C" and "H" cars equipped with a 3.0L and 3.8L engine and THM 440-T4 transaxle, may be repaired by replacing the 3-4 throttle valve (TV) spring. Under light throttle, TCC releases during the shift raising engine rpm momentarily (may be diagnosed as an engine flare), then TCC reapplies shortly after the shift is completed.
DATE OF PRODUCTION
Start of Production for all 1987 THM 440-T4 transaxles.
FIGURE 1 - 3-4 SHIFT VALVE AND THROTTLE VALVE LINE UP:
SERVICE ACTION
Inspect and adjust the TV cable following the procedures contained in the appropriate Service Manual and road test the vehicle. If the condition still exists, replace the 3-4 TV spring (Item #348, Figure 1) contained in the service package described in the "Service Parts Information" section.
SERVICE PARTS INFORMATION
Service Package No. Contents
8662934 (1) 3-4 Throttle Valve Spring
(2) Spacer Plate Gaskets
(1) Instruction Sheet
SERVICE MANUAL REFERENCE
Refer to the On Car Service section and the THM 440-T4 Transaxle Unit Repair section in the appropriate model year service manual for repair procedures.