differential are posi-traction, sure-grip, equal-lock,
Clutch Pack Limited Slip Differential
The clutch pack limited slip differential (fig. 5-17)
uses a set of friction discs and steel plates to lock the
axles together whenever one drive wheel experiences
uncontrolled slippage. The friction discs are
sandwiched between the steel plates inside the
differential case. The friction disc is splined and turns
with the differential side gears. The steel plates turn
with the differential case.
Springs (bellville springs, coil springs, or leaf
springs) force the friction disc and steel plates
together. As a result, both rear axles try to turn with the
Figure 5-16.Differential operation.
Spring force and thrust action of the spider gears
applies the clutch pack. Under high torque conditions,
the rotation of the differential pinion gears PUSHES
OUT on the axle side gears. The axle side gears then
push on the clutch discs. This action helps lock the disc
and keeps both wheels turning.
However, when driving normally, the vehicle can
turn a comer without both wheels rotating at the same
speed. As the vehicle turns a comer, the inner drive
wheel must slow down. The unequal speed between
the side gears causes the side gear pinions to walk
around the side gears. This walking will cause the
outer axle shaft to rotate faster than the differential
case, allowing the pinion shaft on the side to slide
down a V-shaped ramp. This action releases the outer
clutches causing the clutch pack to slip when the
vehicle is turning.