The oil level is low.

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

The engine idle speed is too low.

Refer to Rough, Unstable, or Incorrect Idle and Stalling in Engine Controls.

The oil cooler lines are restricted or leaking.

1. Check the lines for kinks or leaks.
2. Reroute or replace the lines as necessary. Refer to the appropriate procedure:
3. Transmission Oil Cooler Line Replacement

The transmission is excessively leaking oil internally.

Overhaul the transmission. Refer to Allison service manuals.