Spicer Tandem Drive Axles Service Manual D__R440, 460, 480, D_R461, 462, 463, 521, 581, 601, 651, 652, 653 - Manual (Page 142)

138
Theory of Operation
Dual Range Gearing
The gearing for each axle is a combination of a spiral bevel
ring gear and pinion and a planetary unit.
First reduction (High Range) is provided by the spiral bevel
gearing.
Second reduction (Low Range) is through the planetary gear-
ing. Four planetary idler pinions are confined within the ring
gear and mesh with the ring gear internal teeth. The planetary
gears rotate around a sliding clutch gear.
Each axle is equipped with a shift unit, which operates the
sliding clutch gear to provide means for selecting the axle
range. Range selection is accomplished through the move-
ment of the sliding clutch gear in and out of engagement with
the planetary pinions.
High Range
The sliding clutch gear is locked into the high-speed clutch
plate and rotates as part of the differential assembly. The
planetary pin-ions are stationary and the axle uses only the
single reduction of the ring gear and pinion. Power flow is
through the drive pinion, ring gear, differential unit and axle
shafts.
Low Range
The sliding clutch gear is shifted into engagement with the
low-speed clutch plate (an integral part of the left-hand bear-
ing adjuster). The sliding clutch is held stationary and the
planetary pinions are forced to rotate around it. Power flow is
now through drive pinion, ring gear, planetary gearing, differ-
ential unit and axle shafts. The axle uses two reductions to
multiply torque. The planetary unit adds approximately 36%
more reduction to the primary gear set. Torque is multiplied
on an equivalent basis.
1 - High-speed clutch plate
2 - RIng gear
3 - Planetary pinions
4 - Idler pinion pins
5 - Sliding clutch gear
6 - Low-speed clutch plate (bearing adjuster)
1
3
4
2
5
6
1 - High-speed clutch plate
2 - RIng gear
3 - Planetary pinions
4 - Idler pinion pins
5 - Sliding clutch gear
6 - Low-speed clutch plate (bearing adjuster)
1
3
4
6
5
2