Spicer Tandem Drive Axles Pro-40 Single Reduction and Single Reduction with Differential Lock - Manual (Page 92)

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Theory of Operation
Wheel Differential Lock
The Dana Wheel Differential Lock is an optional feature for
Dana Axles. In operation, it positively locks the wheel differen-
tial, to provide improved traction under adverse road condi-
tions.
The differential lock is driver-controlled through an electric
switch or air valve mounted in the cab. The locking mecha-
nism is air-operated to engage a mechanical clutch and lock
the wheel differential. It is spring-operated to disengage the
lock and permit the wheel differential to function normally.
The wheel differential lock consists of three major assemblies.
• Shift Cylinder Assembly: Operates a shift fork and
push rod assembly.
• Shift Fork and Push Rod Assembly: Engages and
disengages the differential lock curvic clutch assembly
• Curvic Clutch Assembly: Consists of a sliding clutch
splined to a axle shaft and a fixed clutch which is
splined to the differential case hub.
The differential lock also includes a selector switch (electric)
which senses clutch engagement and sends an electrical sig-
nal to a cab mounted indicator light (or an audible signal
device).
1— Curvic clutch assembly
1a—Sliding clutch
1b—Fixed clutch
2— Shift fork and push rod assembly
2a—Shift fork
2b—Pushrod
3— Shift cylinder assembly
3a—Piston driver
3b—Selector switch
1
1b
1a
2
2a
2b
3
3a
3b
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