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 0-ring seal in the spacer plate.
To repair this condition, make sure the VCC solenoid screen and/or 0-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 0-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.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.