92C2Targa#119

I am trying to understand how to tell if my option 220 (40/40) limited slip is working properly. I don't think I figured it out from all the comments. How would someone test it such? Could you punch it from almost a dead stop and see if both wheels lay rubber together. Would that work?

ThomasC2

Lift up the rear on one side so you have one rear tires on the ground and the other one in the air. Put the gearbox in neutral, no handbrake, and then try to turn the wheel that's in the air. If you can move the wheel with normal-strong power, it's time to change the discs.

Cupcar

Reading the factory manual, it looks to me as though being able to turn the wheel is normal, it is the torque required to turn it that is important.

The "window" for correct torque is 20 to 50 Nm for a 20-100% variable and 10-35 Nm for a 40% fixed differential, if the torque is above this limit the differential is set too tight, below it the differential is worn or out of adjustment.

So it seems the definition of "normal-strong power" has to be controlled.

Or am I missing something?

YYC930

Cupcar is right.....my tech uses a torque wrench when checking a factory LSD for normal operation. Factory viscous couplings, a la 993 C4, also fail with regularility.

Bill......

I understand that and that is also what it states on their website. Must be the effect of the gears binding on ovverrun and drag taking over to slow the car down and give you the feeling that the rear end is like a solid axle, a la Flintstones.