Limited Slip Differential (Lsd) - Subaru SVX 1992 Manual

AWD SYSTEM [M402] 3-4
4. Limited Slip Differential (LSD)
A viscous coupling (VC) type LSD has been adopted so
as to ensure safe and smooth transfer of increased
power under various driving conditions . This VC type
LSD features ease of turning while maintaining excellent
stability when driving over slippery roads or when using
engine brake, thus enabling engine power to be utilized
efficiently. Smooth restriction of the differential opera-
tion of the left and right wheels results in improved
running stability on bad roads, snowy roads, and also
on muddy roads .
1 . STRUCTURE
The VC type LSD adopts a "shaft to shaft system" in
which the RH and LH rear drive shafts are coupled by a
VC . This results in a compact structure with high perfor-
mance.
The inside of the VC housing is formed by alternately
combining the outer plates (the outer periphery of each
plate engages with the internal spline of the housing)
and inner plates (the inner periphery of each plate
engages with the outer spline of the hub) .
On the outer periphery of the outer plate, the spacer
ring is fitted and set in position . On the inner plate, no
positioning ring is used : The plate can be moved a
certain amount on the hub spline in the axial direction .
Sealed inside the housing is a mixture of high viscosity
silicon oil and air. The housing is sealed by X-rings so
that silicon oil will not leak into the rear final drive even
when the pressure increases due to a greater difference
in the rotation speed between LH and RH wheels .
The spindle (LH) which is integral with the rear drive
shaft (LH) is coupled by the VC case spline, and is fitted
to the side gear (LH) which is integral with the VC case .
The spindle (RH) which is integral with the rear drive
shaft (RH) is spline fitted to the side gear (13H). The end
of the spindle is fitted by splines to the VC hub. No
disassembling of the VC is allowed.
Side gear (LH)
Side gear (R H)
v -
Pinion shaft
Pinion gear
Drive gear
Viscous coupl i ng
C3-129
Fig. 5
2. OPERATION
1) When right and left wheels turn at equal speed
During normal straight-road driving where the right and
left wheels run at an equal speed, the differential case
and side gears rotate together, just as in conventional
differentials . As a result, driving torque is transmitted
equally to the right and left side gears as shown in
Figure 6.
5