Spicer Drive Axles Service Manual Axle Shift Systems, 2-Speed Single Rear Axles - Manual (Page 5)

2
Electric Shift System
General Information
Mechanical Operation
Low to High Range or High to Low Range
When shifting axle range either up or down, motor starts and
turns worm gear shaft. The gear assembly (which is meshed
with worm gear) turns and moves eccentric pin in slot area of
slider block.
Since driving torque holds shift fork and swivel block of the
slider block assembly in place, linear motion of slider block is
translated into compression of the internal spring.
As motor shuts off at 180º of gear rotation, a break in torque
by driver allows spring force (stored in the slider block
assembly) to move the swivel pin and shift fork in appropriate
direction for axle range change.
When opposite axle range is selected by driver, the process is
repeated by motor turning another 180º in same direction. In
this case though, eccentric pin movement creates block
spring compression in the opposite direction.
Note: The new improved housing cover does not require a
gasket (see page 17).
ELECTRIC SHIFT UNIT
Housing Cover
Cover Gasket
Nut (Circuit Board)
Circuit Board Assembly
Red Wire
Black Wire
Green Wire
Cam Pin
Motor Housing
Cover Screw
Cover Gasket
(See Note below)
Wiring Harness
and Connector
Board Flat Washer
Nut (Gear Shaft)
Worm Gear
Motor Screw
Motor Assembly
Nut
Cable Clip
Motor Lead Wire
Electric Shift Unit Assembly
Housing Screw
Nut
Flat Washer (0.100", 2.54 mm thick)
Stud
Seal & Spring
Dowel Pin
Base Housing
Slider Block &
Shaft Assembly
Gear Washer
Gear
Gear Pin
Gear Shaft