TM 5-3895-346-14
AXLE
CARE AND MAINTENANCE
PLANETARY AXLES
CARE AND MAINTENANCE
Planetary axles incorporate a single reduction carrier with bevel or hypoid gearing mounted in the axle center.
The second reduction is of planetary design spur gearing built into the wheel hubs.
Planetary axles permit the bevel or hypoid gearing of the carrier and the axle shafts to carry only a nominal
torsional load while at the same time providing the highest practical numerical gear reduction at the wheels.
The hypoid pinion and differential as- sembly of the first reduction are sup- ported by tapered roller bearings.
The pinion-bearing preload is adjusted and maintained by a hardened precision spacer between the inner and
outer bearings. The differential tapered bearing preload is adjusted and maintained by the positioning of the
threaded adjusting rings in the carrier leg and cap bores.
The spur teeth of the sun gear (which floats) mesh with teeth of the planet spur gears. The planet spur gears
ro- tate on planet pins which are mounted in a spider. The planet spur gear teeth inturn mesh with teeth of the
floating ring gear.
Power is transmitted by the pinion and gear of the first reduction to the axle shafts empowering the sun gear of
the second reduction, through the revolving planet gears, and into the planetary spider which drives the wheel
hub.
The servicing of the single reduction carrier assembly used in the planetary housing center is thoroughly
covered in our Field Maintenance Manual No. 5 (or 5A if drive unit is the through-drive type).
Figure 1. Planetary Rigid Types (PR)
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