GM Service Manual Online
For 1990-2009 cars only

Problem

Action

The oil level is low.

Add oil in order to obtain the proper oil level. Refer to Transmission Fluid Check .

The clutch main pressure is low.

Test the pressure.

The forward clutch is slipping.

  1. Repair the forward clutch.
  2. Refer to applicable Allison Transmission Service Manual.
  3. Replace the piston seals.

Refer to applicable Allison Transmission Service Manual.

The seal rings on the front support hub are broken.

Replace the seal rings.

Refer to applicable Allison Transmission Service Manual.