LA Porsche and BMW Repair

Servicing the Cayenne Automatic Transmission

We were contacted recently by a PCA club member who asked if it would be possible for him to perform a service on the automatic transmission in his Cayenne. The answer is a qualified yes, it is possible; however, having the required tools and the procedural knowledge for performing this service is critical. After documenting this information, we thought that it might provide an interesting insight for club members as to what is involved in performing this important service for the Cayenne. This is also somewhat indicative of servicing the later model Tiptronic transmission equipped Porsche’s.

We recommend you warm up the engine to operating temperature. Drive the vehicle and make sure that the transmission operates properly; shifting correctly in all gears and speeds. Let the car cool down overnight before starting the transmission service. Be prepared to dispose of the fluid and filter properly due to the hazardous waste implications.

Porsche recommends also draining the transmission cooler when servicing the automatic transmission. Consult the factory manual for this additional procedure.

Note: this process will require two people when refilling the transmission fluid.

Required tools and parts:

• The Porsche PIWIS (Porsche Integrated Workshop Information System) diagnostic tool for proper filling of transmission fluid and performing transmission adaptation procedure
• 12 – 14 liter capacity fluid container
• Assorted metric sockets, wrenches and screwdrivers
• 1/4” drive IN/lb. torque wrench
• 3/8” drive FT/lb. torque wrench
• Cleaning materials (solvent) and towels (Lint free towels are imperative for this procedure)
• Transmission filter screen (Genuine Porsche Preferred)
• Transmission filter screen O-ring (Genuine Porsche preferred)
• Transmission oil pan gasket (Genuine Porsche preferred)
• 10 Liters of genuine Porsche transmission fluid (oil)
• Oil pump with reservoir and hose (for filling the transmission with fluid-oil)

Transmission service procedure:

1. Perform these procedures with the vehicle turned off and the parking brake firmly set. You might want to put the car keys on the workbench or similar place but not in the ignition or in the car where it could inadvertently be started while the service is taking place.
2. One important tech note is to make sure that you never set the alarm/key remote near a strong magnet or in a magnetic tray. This might accidentally remove the memory of the electronic alarm/key remote.
3. Remove the transmission under-body panel.
4. Remove the oil drain plug; drain the automatic transmission fluid into a suitable container capable of safely handling at least 12 liters of fluid (oil). Replace the oil drain plug sealing washer and torque the drain plug to 21 FT/lbs. Transmission oil drain plug (10mm x 1.00mm).
5. Remove all transmission oil pan fasteners and then the transmission oil pan.
6. It is imperative that you smell the transmission oil to make sure that it is not burnt, this is critical in the process of servicing any transmission. If you are not aware of what the transmission oil should normally smell like, you might want to consult with a specialist. If the oil is burnt, the transmission is in need of additional repairs.
7. Visually inspect the transmission pan very closely for any bits, metal particles or other (Clutch) debris. If an excessive amount of debris is found, this usually indicates a pending internal transmission failure. If necessary, consult with a specialist. Normally there is no debris. The 5 oil pan internal magnets should be in their correct positions.
8. Replace the transmission filter screen and filter screen O-ring, lube new ring with fresh ATF oil. Torque the filter screen fasteners to 90 IN/lbs.
9. Install the transmission oil pan with a new oil pan gasket. Torque all oil pan fasteners to 90 IN/lbs.
10. Remove the transmission oil inspection plug (24mm x 1.5mm); fill the transmission with fluid until it overflows slightly. This will require a reservoir, fluid pump and hose.
11. Have a second person inside the vehicle that will be utilizing the PIWIS diagnostic Tester and will be paying close attention to the transmission oil temperature.
    Start the car while the other person continues to add fluid to the transmission, stop adding fluid once it overflows. As the engine and transmission are warming up, the transmission should be overflowing some fluid. While fluid is still being added as needed, the person inside the vehicle should firmly apply the foot brake and shift through all gears a few times while at idle speed. Please note: If you see foamy ATF oil exiting the oil inspection plug hole, stop and call a professional, this usually indicates a problem.
12. Put the vehicle in Park, once the transmission reaches 40°C and only a slight amount of fluid is overflowing, it is now full of fluid and the oil inspection plug can be reinstalled. Torque the oil inspection plug to 25 FT/lbs. Note: we also recommend adding the aftermarket transmission fluid additive Lubegard with patented LXE®, part number 60902, and use one 10oz container per transmission service.
13. Test drive the vehicle. After the test drive, inspect the transmission carefully for any fluid leaks and reinstall the under-body paneling. Tighten all sheet metal screws by hand and torque the under-body panel bolts to 90 IN/lbs.

Porsche also recommends performing a “Transmission Initial Adaptation” after servicing the automatic transmission. Consult the factory manual for this additional procedure.