[Dandelion]

Originally Posted by Mark Hubley

Last December I bought a 2015 Cayman GTS. According to the seller, and according to the Certificate of Authenticity that came with the car, it has the Porsche Torque Vectoring option. According to information I see on the Interwebs, PTV includes a limited slip differential. So, I have been assuming my car has an LSD.

Recently, I had the car on my lift to swap wheels. While I had the car up in the air (and transmission set in 1st gear), I rotated one of the rear wheels (forward direction), and I noticed the other spun in the opposite direction (as if in reverse). I was under the impression that if a car has an LSD, both wheels will rotate in the same direction.

Does this mean my car does not have a limited slip diff?
Or maybe with this particular LSD it is normal for the wheels to rotate in opposite directions when testing like this?

What do the wheels do when the car is in neutral and you spin one side while on the lift?

ed

[HoodPin]

Originally Posted by Dandelion

What do the wheels do when the car is in neutral and you spin one side while on the lift?

ed

I was wondering the same. I've normally checked for LSD wheel rotation with the trans in neutral. On a normal rear axle, driven by a driveshaft, it shouldn't make a difference. But on a transaxle, I wonder if having it gear changes the behavior.

[Mark Hubley]

Thanks for all the input. I got the following feedback from someone on Rennlist:

"All of the late model Caymans have a zero preload LSD. What this means is that while it has clutches, there are no spring washers, so it has no resistance and when a wheel is spun it acts like it’s open. This will apply to PTV vehicles regardless of whether they are 6spd or PDK."