Cab... one of the factors some forget is that the rear
end is trying to spin around the drive shaft... if
you could hold the drive shaft with the rear end
not in the car the rear end housing would spin in
circles... its trying to do the same in the car..
the RR tire is trying to go up and the LR tire is
trying to go down... thats why the LR tire tends
to do more work and tends to drive the car to the
right... so you need to help equalize the tire loads
by adding the pre-load to the RR.. the amount of torque
and the chassis flex dictate the pre load