In this article, I will go over the steps involved with changing the front differential oil on your Porsche Cayenne. Changing the oil is not a difficult job, but can be a bit messy. It is advisable to lay down a plastic tarp or sheeting underneath the car to catch any possible spills. You'll also want to have a drain pan with a capacity of at least five liters to be on the safe side. When filling the front differential, you'll need roughly one liter of Porsche approved gear oil.
Begin by jacking up the Cayenne and securing it on four jackstands (See our article on Jacking Up Your Cayenne for more information). This is both to gain clearance to the rear differential and also to keep the Cayenne level. This is important. If you do not have the car level, it will affect the measurement for filling the differential back up. Note, if you have air suspension on your Cayenne, it is possible to gain enough clearance to access the transfer case by putting the suspension to its highest setting.
Now remove the lower engine cover to gain access to the front differential (see our article on Removing Under Body Trays for more information). It is located just to the right of the oil pan. You'll find that the fill plug is located just behind one of the crossmembers. This can make removal a bit difficult as a regular sized hex key will not fit. I had to cut 10mm off the end of an 8mm hex key. This allowed me to insert it into the fill plug.
Note that Porsche recommends replacing the drain plug seals each time you remove the plugs. At this time it appears that Porsche is only selling the seals with new drain plugs. (part number 955-332-057-00). I would visually inspect each seal first for damage or wear before automatically replacing it.
Shown here are the drain (yellow arrow) and fill (green arrow) plugs on the front differential.
You'll want to remove the fill plug first to help drain the oil from the differential. Use the modified 8mm hex key (green arrow) to loosen and remove the plug. Once the fill plug is removed, remove the drain plug (yellow arrow) and let the differential drain completely. Make sure you have a drain pan underneath to catch the old fluid. Inspect the sealing ring on the drain plug. Now replace or reinstall the plug and torque it to 35Nm (26 ft/lbs.). Use a hand pump to fill the differential with gear oil until it just starts to pour out the fill plug threads. Now either replace or reinstall the plug and torque it to 35Nm (26 ft/lbs.).