WORKHORSE CUSTOM CHASSIS
Service Manual
2007 W Series
SECTION
7.2
PAGE
88
Automatic Transmission – Allison
2007 W Series Chassis
© 2006 Workhorse Custom Chassis — All Rights Reserved
WSM082106
Default Reverse - Limp Home
If electrical power is interrupted with the transmission
operating in reverse range, resulting in neutral
operation, main pressure is directed through shift valve
3 to shift valve 2. Because shift valve 2 stays stroked
due to the “latching” effect of pressure on two different
diameter lands, main pressure is blocked from reaching
the manual selector valve. If the manual selector
valve is moved to Neutral (N) or a forward range, the
transmission remains in neutral.
If electrical power is interrupted with the transmission
operating in reverse range, resulting in neutral operation,
the engine may be shut down and restarted to attain
neutral, third and reverse operation.