CONTROL SYSTEM OPERATION (Contd)
TRANSFER CASE SHIFT LEVER SWITCH - When depressed with transmission in neutral, signals interlock
solenoid valve to exhaust air pressure from interlock air cylinder and actuates lock-up solenoid.
TRANSFER CASE SHIFT LEVER - Is pushed down to high for light load operations, and up to low for heavy
load operations. Six-wheel drive is achieved automatically when transfer case shift lever is placed in low.
TRANSFER CASE POWER TAKEOFF CONTROL LEVER - Manual control for engaging power takeoff.
TRANSFER CASE POWER TAKEOFF - Mounted and mechanically driven at rear of transfer case, the PTO
drives a pump to supply hydraulic pressure to power the rear winch and crane on the M936/A1/A2 wreckers.
FRONT-WHEEL DRIVE LOCK-IN SWITCH - Manual control for activating front-wheel drive valve to provide
front-wheel drive with transfer case in high drive range.
INTERLOCK AIR CYLINDER - Under air pressure, a piston in the interlock air cylinder forces a shaft against
one of three grooves in transfer case shift lever. This prevents transfer case from being shifted with
transmission in gear.
INTERLOCK SOLENOID VALVE - Releases air from interlock air cylinder when transmission is in neutral
and transfer case shift lever switch is depressed. This permits the transfer case high/low shift shaft to move.
FRONT-WHEEL DRIVE AIR CYLINDER - When under pressure, it moves transfer case clutch forward to
engage front-wheel drive.
FRONT-WHEEL DRIVE VALVE - When tripped by transfer case shift shaft, the front wheel drive valve routes
air to front-wheel drive air cylinder.