The cooler lines are restricted.

1. Remove the restrictions.
2. Clean or replace the lines as necessary. Refer to the appropriate procedure:

•	Transmission Oil Cooler Line Replacement

•	Transmission Oil Cooler Line Replacement

•	Transmission Oil Cooler Line Replacement

•	Transmission Oil Cooler Line Replacement

The torque converter has broken parts.

Repair or replace the converter assembly. Refer to Allison service manuals.

The oil is aerated.

Check the following:

Refer to Allison service manuals.

Internal leakage is slowing the oil cooling flow.

Overhaul the transmission. Refer to Allison service manuals.