The Porsche 996 (911) turbo is an exceptional piece of automotive engineering, as evidenced by its years of success in the market and its history of winning and dominating in different series and racing competitions around the world.
As such, repairs and upgrades to this fantastic car need to be approached a bit differently than other vehicles. The way the different car components and systems are designed and function is a bit different than the typical everyday car and as a result requires expert knowledge and understanding to perform upgrades and maintenance on these vehicles.
Here we will focus on the Porsche 996 clutch and related repairs.
For example, the clutch system on this car is different from other vehicles on the market. The Porsche 996 turbo’s clutch is hydraulically assisted, so even when high-pressure clamping-load plates are installed, pedal effort does not change. The biggest difference in the system compared to other cars is in the design of the slave cylinder. The hydraulic power assist system works by using the power steering system’s high pressure circuit to charge an accumulator that is part of the slave cylinder assembly to reduce the effort required to operate the slave cylinder.
A good and detailed understanding of this system is required to perform jobs such as clutch component replacement correctly and to factory specifications.
Another big difference in the way the clutch system works on the 996/997 turbo compared to other cars is the pressure plate release mechanism. The majority and most common form of pressure plate release operation is of the push type, while on the Porsche 996 turbo it is of the pull type. While this may seem like a very small and minor detail, it is not, as the procedure required to separate the gearbox from the engine is completely different. The biggest and most difficult aspect of the job is removing and reinstalling the pivot pin that the release lever attached to the waste bearing operates on. This pin must be removed (slid out) before the gearbox can be disassembled and must be fitted during reassembly after the motor and gearbox have been mated. If you have ever seen this assembly you will understand how difficult it is to line up the holes in the release lever with those in the bell as there is no way to see them and it must be done by feel. Additionally, the pin has roller bearings at both ends that house small steel rollers inside and can slip off the shaft if pulled back during insertion. If this happens, it will be necessary to remove the gearbox again to retrieve the rollers and assemble the bearings.