WORKHORSE CUSTOM CHASSIS
Service Manual
Automatic Transmission – Allison
2007 W Series
© 2006 Workhorse Custom Chassis — All Rights Reserved
SECTION
7.2
PAGE
481
2007 W Series Chassis
WSM082106
TRANSMISSION OVERHEATS
Condition
Action
Aerated fluid - incorrect fluid level
• Adjust fl uid to the proper level. Refer to Transmission Fluid Checking
Procedure .
• Inspect for a defective pump.
Air flow to cooler obstructed
Remove the air flow obstruction.
Engine overheat
Correct the overheating condition. Refer to Symptoms - Engine Cooling in
Engine Cooling.
Inaccurate temperature gauge or sending unit
Replace the gauge and/or sending unit.
Inaccurate sump temperature sensor
Replace the pressure switch manifold (PSM) or internal harness. Refer to
Pressure Switch Manifold Replacement or Wiring Harness Replacement.
Excessive cooler circuit pressure drop
Inspect for plugged cooler, lines too small, collapsed hose, too many elbows
in circuit.
Transmission cooler lines reversed
Connect the cooler lines properly. Oil and water should flow in opposite
directions.
Fluid cooler lines restricted
Remove restrictions and clean or replace the lines. Refer to Transmission
Fluid Cooler Hose/Pipe Replacement.
Torque converter - wrong converter, no torque converter clutch,
stuck stator, or slipping stator
Replace or repair the converter assembly. Refer to Torque Converter
Replacement .
A stuck stator will not allow cool down in Neutral.
Cooler flow loss due to internal transmission leakage
Overhaul the transmission.
