Leaks

There are a number of locations where leaks can occur on the 7 speed PDK. Below are images and descriptions of the most common.

Pan leaks

I haven’t shown an image, but leaks can develop around the black pan at the base of the transmission. This can be corrected by pan replacement. I’ve had numerous reports from people who complain of leaks after replacing the black plastic pan with an aftermarket aluminium pan.

Vent leaks

On the right is an image of the top of a transmission showing the two transmission vents. These are there to allow for expansion/contraction of the air inside during temperature changes.

There is really nothing that can be done about these leaks apart from installing some type of aftermarket device that will catch the fluid. It is unusual to have leaks from here when street driving. But track drivers do report leaks from these locations sometimes.

Note the image is of a 981 transmission. Other transmission variants may have the vents in a different location.

Front cover leaks

Image of the transmission removed from the car shows where leaks can occur from the 6 O’clock position on the bell housing. These can come from the outer seal on the clutch cover, but most likely from the clutch input seal. This often occurs due to a failing dual mass flywheel (DMF), which in turn shakes the clutch pack and creates the leak.

Half shaft seal leaks

On the half shafts located behind the differential there is a double seal that separates the clutch and gear section fluids in this location. The image below shows the location of the seals and where leaks will occur from the weep hole below the bell housing.

I’ve provided a video that shows an explanation of the seals being replaced.

Note that displacement of the seals is commonplace when the rear wheels take a hit during an accident. This occurs regularly during track operations. Not ensuring these seals are located correctly is a common cause of gear/clutch fluid mixing, which can cause many issues afterwards.

Internal double seal leaks

There is a set of double seals on the input shafts that are right in the middle of the transmission. These seals separate the two fluid types in this area. The leak comes from the hex plug on the side of the transmission as shown in the image. This image shows the plug on a 911 transmission. The Boxster/Cayman transmission has this plug on the other side.

Fixing this leak is very difficult and requires a complete disassembly of the transmission and gearset. I only know one person with the skills, tools and knowledge for this. Many transmissions are shipped to him to correct the leak

Jay Lawlor at Speed Density Motorsports has developed the seals himself (they aren’t available from Porsche). He also developed his own in-house tools to fully disassemble the transmission so the seals can be replaced. The video linked is him showing the seals, their location in the transmission and how the weep plug works.