Spicer Tandem Drive Axles Service Manual D__R440, 460, 480, D_R461, 462, 463, 521, 581, 601, 651, 652, 653 - Manual (Page 122)

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Dual Range Axle Shift Systems
Axle Range Interlock Operation
Engage Lockout (Lock Differential) (Axle in High or Low
Range)
1 - Reservoir air pressure
2 - Air pressure
3 -Air pressure (from lockout shifter
valve) moves piston to engaged lockout
4- Lockkout cylinder piston movement
allows interlock control valve to open 5 - Air pressure is applied to the interlock
pin. Pin moves to block shifter valve le-
ver. Axle range cannot be changed.
6 - Interlock pin assembly
7 - Axle range shifter valve
8 - sliding clutch engages helical - side
gear
9 - Lockout cylinder 10 - Lockout cylinder
11 - Interlock control valve