A/T - 440-T4 Harsh 1st to 2ng Gear Upshift
88cad06Bulletin No. T-88-147
File in Group 7
Number 190
Corp. Ref. No. 877126
Date June '88
SUBJECT: HARSH 1-2 UPSHIFT - THM 440-T4
MODELS AFFECTED: 1985-1988 DE VILLES AND FLEETWOODS 1986-1988 ELDORADOS AND SEVILLES
Some 1985-1988 DeVilles and Fleetwoods, and 1986-1988 Eldorados and Sevilles may experience harsh 1-2 upshifts due to VCC apply in 2nd gear. Symptoms of a 2nd gear apply include:
^ VCC applies during 1-2 shift.
^ VCC applies in 2nd gear during acceleration, releases at steady throttle in 2nd gear.
^ VCC appears not to apply in 3rd gear because it already applied in 2nd gear.
This may be caused by a missing or mispositioned VCC solenoid screen and/or O-ring seal in the spacer plate.
FIGURE 1 - VCC SOLENOID SCREEN LOCATION:
To repair this condition, make sure the VCC solenoid screen and/or O-ring seal is not missing or mispositioned when the valve body is removed from a THM 440-T4, refer to Figure 1. 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 is missing, worn, or damaged, replace it with a VCC solenoid screen assembly, P/N 8658060. If the O-ring seal is missing or worn, a new one can be ordered using P/N 8658109.
Refer to the THM 440-T4 Automatic Transaxle Unit Repair section of the appropriate Service Information Manual.