Subaru Impreza 2002 Service Manual page 67

FRONT DIFFERENTIAL (SURETRAC TYPE LIMITED SLIP DIFFERENTIAL)
Manual Transmission and Differential
3. WHEN TRACTION IS DIFFERENT BETWEEN RIGHT AND LEFT WHEELS
For example, if the left wheel spins on a slippery surface and loses traction, the left face cam starts
rotating at a speed faster than the right wheel.
Like when the right and left wheels rotate at different speeds mentioned earlier, the cam follower
A starts moving to the left.
This time, however, as the right wheel has traction, the drive torque pushes the cam follower A
strongly against the right face cam when it makes the cam follower get over the slope B of the face
cam, generating a large friction force between the contacting surfaces (shown by a thick line in
the drawing).
This large friction force allows the drive torque to be transmitted to the right wheel.
In this way, the SURETRAC differential can keep the drive torque distributed to a wheel with traction
even when the other wheel spins and loses traction.
(1) Cam follower
(2) Face cam
D: SERVICE PROCEDURES FOR LSD
It is not recommended to disassemble this LSD assembly as components of this LSD assembly
are not available individually.
(A) High speed rotation
(B) Low speed rotation
6MT-28
NF0565