
20 Final drives and rear axles
20.1 FINAL DRIVE GEARS AND BEARINGS
The purpose of final drive gears
Final drive gears are incorporated in vehicle driving
axles for the following reasons:
1 To provide a right-angled drive from either the pro-
peller shaft, or the gearbox layshaft, to the driven
wheels.
2 Alternatively, to provide a parallel drive from the
gearbox layshaft to the driven wheels.
3 To permit an additional and constant gear reduction
in the transmission system.
The first requirement will be fairly evident and it
derives from the particular layout of the vehicle. It
therefore applies to any vehicle in which a longitudinal
mountin