WORKHORSE CUSTOM CHASSIS
Service Manual
2007 W Series
SECTION
7.2
PAGE
480
Automatic Transmission – Allison
2007 W Series Chassis
© 2006 Workhorse Custom Chassis — All Rights Reserved
WSM082106
TRANSMISSION WILL NOT SHIFT TO FORWARD OR
REVERSE
Condition
Action
Engine RPM too high
Reduce the engine RPM. It may be necessary to select NEUTRAL, and
then D or R again.
Low fluid level
Add fluid to the proper level. Refer to Transmission Fluid Checking
Procedure.
Faulty throttle signal from engine
Correct the engine throttle signal.
Shift selector is not functioning properly
Repair the shift selector.
Speed sensor or sensors not functioning properly
Repair or replace the speed sensor or sensors or circuitry. Refer to Speed
Sensor Replacement.
Mechanical failure to Low and Reverse clutch
Repair the transmission.
Mechanical failure in transmission torque converter, shafts, or
planetaries.
Repair the transmission.
Low pressure
Repair the transmission.
Faulty wiring in transmission control module (TCM) input/output
function circuits
Correct the circuit wiring.
