Lumina L4-151 2.5L (1991)
V.
HARSH UPSHIFTS - HIGH ALTITUDE ONLY
-
1985-86 A Cars with 2.8L engines
Service Procedure:
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.
Based on vehicle applications, each package contains:
A Cars with 2.81 Engines Only
(1)
Vacuum Modulator Assembly
(1)
Modulator Valve
(1)
O-Ring Seal
(1)
Instruction Sheet
Service Parts Information:
Service Package
Transaxle Model Identification
Number
(Refer to Figure 1) Identification Information
8646956
6CFH, 6CMH, 6HBH, 6HJH
5CM, 5CN, 5CP, 5CW, 5HA, 5HJ, 5HT
8646966
6AAH, 6ACH, 6AFH, 6AMH
5AF, 5AM
8646967
6ADH, 6ARH
Parts are currently available from GMSPO.
Service Notes:
A new vacuum line from the engine to the vacuum modulator MUST also be installed when using the service packages listed above.
Part Number
Vehicle Application
14062624
A Car
Parts are currently available from GMSPO.
Other items affecting harsh upshift conditions are:
-
engine vacuum leaks
