Francin728

I have a 2006 Cayenne S Titanium. I'd like to change the rear end and differential fluids with Motul gear 300 75W-90 oil. How do I go about finding out if my car has a limited slip differential?

knfeparty

None of them have limited slip that I know of.

Off road technology package cars (with the swaybar disconnect button) have locking rear diffs; everything else is open.

wrinkledpants

No limited slip diff was offered. However, the rear with a locker option does require a friction modifier. It's still an open diff when it's not locked.

If you have a blank button next to the diff switch, then you don't have the offroad tech package (which has the rear locker). If you have the sway bar disconnect button next to the diff switch, you have the rear locker. You can also visually look at the rear diff, too. The locker rear will have a soda can sized motor hanging off of it with a wire harness. It will be right above the sub-frame. Or, you can put the car in neutral and flip the diff switch forward. Flip it once to engage low-range, again for the longitudinal lock (T-case), and flip it a 3rd time for the rear locker. If you don't have the rear locker, nothing will happen after you flip it the third time.

Without the rear locker, the front and rear diffs will take the same fluid.

hahnmgh63

My CTTS has option I1Y1 which is listed on the build sheet as Limited Slip Differential lock, rear, centre differential lock - Electric. I'm not sure what that means as wrinkled pants mentioned, it does require a friction modifier?

wrinkledpants

Yeah - it's odd they label it that way. LS and lockers are often two different things, though there are a couple companies that make LS lockers. Porsche wouldn't add an LS diff that's only part of the "off road package" when it's also adding a locker. If anything, there would be an LS option on all cars since the LS would be most prevalent on the street, and the locker for the off road pack. But, the LS would be redundant since the Cayenne has such a good EDL system.

Many lockers require an friction modifier, FWIW. So, makes sense that it would spec that if you have the off-road pack.

J'sWorld

If you have a locker there will be an electric motor on the diff housing with an electrical plug going to it. This style of locking diff uses a retracting pin to lock and unlock the spider gears. You don't need a friction modifier because there is no clutch pack.