Harsh Upshifts - High Altitude Only Information

VI. Harsh Upshifts - High Altitude Only

1985-86 Cutlass Ciera Equipped with 2.8L Engine and 440-T4 Transaxle

Service Action:

Harsh upshifts at high altitudes may be caused by high line presure due to low engine vacuum. This condition may be corrected on certain transaxle models by installing the appropriate aneroid modulator service package

Service Package Contains:
(1) Vacuum Modulator Asm.
(1) Modulator Valve
(1) O-Ring Seal
(1) Spacer Plate
(5) Gaskets
(1) Cup Plug (Orificed)
(2) Instruction Sheets

(1) Vacuum Modulator Asm.
(1) Modulator Valve
(1) O-Ring Seal
(1) Instruction Shoot

FIGURE 1 - THM 440-T4 TRANSAXLE IDENTIFICATION INFORMATION:

Service Parts Information:

Service Transaxle Model
Package Number Identification (Refer to Figure 1)

8646956 6CFH, 6CMH, 6CNH, 6HBH, 6HJH
8646956 5CM, 5CN, 5CP, 5CW, 5HA, 5HJ, 5HT

8646966 6AAH, 6ACH, 6AFH, 6AMH,

8646966 5AF, 5AM

8646967 6ADH, 6ARH

Service Notes:

A new vacuum line from the engine to the vacuum modulator must also be installed when using the service package listed above.

Part Number - 14062624

Other items affecting harsh upshift conditions are:

- Engine vacuum leeks
- Sticking Modulator valve
- Restrictions in the vacuum lins such as point in the modulator tube or other foreign material.