Toronado V6-231 3.8L (1986)
Valve Body: All Technical Service Bulletins
A/T - Harsh or Firm 2-3 Upshifts
SUBJECT
HARSH OR FIRM 2-3 UPSHIFTS
MODELS/YEARS
1986 (S.R.T.A.) OR 1987 440T4/HYDRA-MATIC 4T60
EQUIPPED CUTLASS CIERA, EIGHTY-EIGHT, NINETYEIGHT, AND TORONADO WITH 3.8L (RPO - LG3) ENGINE
NUMBER:
87-T-76
CORP.REF.NO: 977108
DATE:
March 1989
SECTION:
7A
BULLETIN COVERS: (Figure 1)
A harsh or firm 2-3 upshift that may occur most noticeably under 1/2 throttle acceleration on some 1986 SRTA models and 1987 Cutlass Ciera,
Eighty-Eight, Ninety-Eight and Toronado models equipped with a 3.8L and THM 440-T4/HYDRA-MATIC 4T60 transaxle. This condition can be
corrected by following the procedure listed under "Service Action:".
Figure 2 - 3-4 MTV And 2-3 Accumulator Valve Trains
SERVICE ACTION:
1.
Verify correct minimum and maximum pressures.
2.
Check for vacuum leaks and/or a low vacuum supply to the vacuum modulator. Required vacuum is 44-61 KPa (13-18 in.Hg.). The vacuum signal
should respond quickly to throttle movement; if not, check for anything that could cause a vacuum restriction to the modulator causing a delayed
response to throttle movement, like paint in the modulator tube and/or carbon at the throttle body fitting.
3.
Remove the 3-4 M.T.V. Bushing (338), 2-3 Accumulator Valve (337), then the 2-3 Accumulator Spring (336) as shown in Figure 2. Install the 2-3
Accumulator Spring (336) from the appropriate service package shown in the "Service Parts Information" section.
While the transaxle is disassembled, check the items listed below that affect transaxle operation which may also contribute to the harsh shift
condition.
-
# 7 Check Ball and Capsule for leaks.
-
1-2 Servo Pipe for leaks.
-
1-2 Servo for seal damage or binding.
-
# 12 Check Ball missing, or mislocated.
-
Spacer Plate for peening from Check Balls # 4 and # 12.
