Subaru LEGACY 2002 Quick Reference Index page 326

Manual Transmission and Differential
B: DUAL-RANGE MODEL
The dual-range manual transmission is of a full-time all-wheel-drive design integrating a transmis-
sion assembly, front differential, and transfer gear assembly with center differential into a single
unit. The transmission creates five forward speeds and one reverse using the corresponding gears
all provided with inertia lock-key type synchronizers.
The transmission and front differential are housed in an aluminum case which is split into right and
left halves and constitutes also a clutch housing. Located at the rear and joined each other are the
transfer case and extension case which house the transfer gears and center differential as well as
part of the transmission assembly.
The major features of the transmission are as follows:
! The forward speed gears are helical gears featuring high tooth face strength, large tooth contact
areas, and quiet operation.
Reversing rotation is achieved by making a slidable reverse idler gear engage with both the re-
!
verse drive gear on the mainshaft and the reverse driven gear integral with the 1st-2nd synchro-
nizer hub on the drive pinion shaft.
The 1st driven gear on the drive pinion shaft has a subgear which helps reduce noise during
!
engagement.
The center differential compensates for the difference in front and rear axle speeds. It consists of
a bevel gear set and a viscous coupling located at its rear end which are housed in a single case.
The center differential, together with a pair of transfer gears, transmits the power from the trans-
mission to the drive pinion shaft (front wheel drive shaft) and the rear drive shaft. The viscous cou-
pling functions as a differential-action-control element.
On the part just above the front differential of the input shaft, there are auxiliary transmission gears
of synchromesh design. They provides a dual-range function that allows the driver to select "high"
or "low" range as desired. Switching of the range is possible even during driving if the clutch pedal
is depressed and then the range selector lever is moved.
GENERAL
MT-4