L322 Range Rover System Description and Operation
TRANSFER BOX
DESCRIPTION AND OPERATION
41-11
A filler/level plug is provided to ensure that the correct oil level is achieved after a service repair has been carried out.
The level must be checked and adjusted with the transmission fully assembled and the vehicle on level ground. The
transfer box contains 0.996 litres of oil. The transfer box is a fill for life unit and no level check is required at service
unless a leak is present.
Planetary Gearset
The planetary gearset comprises a front and rear carrier half, an input shaft, four planet pinion gears, four planet pinion
shafts and one hundred and forty four needle rollers.
The input shaft is located through the planetary carriers and is driven by the output shaft from the transmission. The
sun gear is located on splines on the input shaft and rotates at the same speed. Rotation of the sun gear is transferred
to the four pinion planet gears which in turn rotate around an annulus gear located in the front casing and secured
with a retaining ring.
The rotation of the planetary pinion gears causes the front and rear carriers to rotate. The rear carrier has gear teeth
which mesh with the teeth in the sleeve. To smooth the transition of the gear teeth of the sleeve and the rear carrier,
an inner and outer blocker ring and a cone are fitted. When the fork moves the sleeve, the three detents in the hub
are pushed, which in turn push the inner and outer blocker rings and the cone together. These items mesh together
at an angle and operate as a synchromesh to provide smooth engagement of the gear teeth and the transition into
low range.
The input shaft also has an outer blocker ring and a cone between the shaft and the hub. When the fork moves the
sleeve, the three detents in the hub are pushed, which in turn push the outer blocker ring and the cone together. These
items also mesh together at an angle and operate as a synchromesh to provide smooth engagement of the gear teeth
of the hub and the input shaft and the transition into high range.
Fork and Rail Assembly
The fork and rail assembly is the main component for changing from high to low ratio and is driven by the actuator
assembly and the lead screw. The actuator rotates the lead screw, via the gearbox, which in turn moves the fork and
rail assembly linearly in plain bearings in the front and rear casings. The fork is positively located in a stepped ring on
the outer diameter of the synchroniser sleeve. Therefore, linear movement of the fork is transferred to the sleeve
which initiates the range change.
