Harsh Upshifts - High Altitude Only:

1985-86 Cutlass Ciera/Cruiser With 2.8L Engine

Harsh upshifts for ALL GEARS at high altitudes may be caused by high line pressure due to low engine vacuum. This condition may be corrected on certain transaxle models by installing the appropriate aneroid modulator Service Package.


A new vacuum line from the engine to the vacuum modulator, P/N 14062624, MUST also be installed when using the service packages.

All parts listed in this bulletin are currently available from GMSPO.

Other items affecting harsh upshift conditions are:
^ Engine vacuum leaks
^ Sticking modulator valve
^ Restrictions in the vacuum lines such as paint in the modulator tube and/or carbon at the throttle body fitting