GM Service Manual Online
For 1990-2009 cars only

Slips in Reverse or No Reverse

Checks

Cause

DEFINITION: A large engine RPM increase is noted with little or no vehicle rearward speed increase during the following conditions:

    • The engine is running.
    • The transmission is in Reverse range.
    • The vehicle is stopped or moving slowly.
    • The vehicle brakes are not applied.
    • The throttle is opened 25 percent or greater.

Automatic Transmission Fluid Level

Low fluid level

Transmission Main Line Pressure

Low transmission main line pressure

Manual Linkage

Misadjusted

Oil Filter Assembly

    • The oil filter assembly (100) is missing, plugged, or damaged.
    • The oil filter seal assembly (101) is missing or damaged.

Reverse Band Servo Assembly

    • A servo piston oil seal ring (43) is missing or is damaged.
    • A servo piston (44) is damaged or is stuck in the case bore.
    • The servo piston cushion springs (45, 47) or the retainer (46) is missing or damaged.
    • The servo piston pin (48) is not engaged to the reverse band assembly (615).
    • The reverse band assembly (615) is worn or burned.
    • The reverse band assembly (615) is disengaged from the anchor pin (117B) band.
    • The anchor pin (117B) is loose or missing.

Torque Converter Assembly

The torque converter assembly (1) stator clutch is not holding.

Drive Link Assembly

    • The drive link assembly (507) is broken.
    • The drive/driven sprockets (516/506) are damaged.

Input Clutch Assembly

    • The input clutch sprag assembly (722) is damaged or misassembled.
    • The input clutch housing oil seal rings (628) are missing or are damaged.
    • The input clutch housing ball check valve assembly (633) is missing or is damaged.
    • The input clutch piston inner/outer seals (634/635) are missing or are damaged.
    • The input clutch piston (636) is damaged.
    • The input clutch plates (654-658) are worn.

Reverse Reaction Drum

The reverse reaction drum (669) splines are damaged.

Input and Reaction Carrier Assemblies

The input carrier assembly (672) or the reaction carrier assembly (675) components are damaged.

Differential Carrier Assembly

    • The park pawl assembly (694) is broken or damaged.
    • The sun gear shaft (689), the internal gear assembly (693), or the carrier assembly (700) components are damaged.