The Flex Plate Clamp issue can affect any 928 fitted with an Automatic transmission from 1984 onwards. The problem is where Porsche changed the design of the clamp so that in some circumstances the drive shaft can move forward, putting huge pressure on the flex plate, which can lead to Thrust Bearing Failure (TBF). This is a catastrophic event, leading to the total loss of the engine and huge bills for the owner. The solution has been regular checking and relieving of flex plate pressure, as described in detail in this PDF.
UK company Ritech Systems has come up with a solution, which is designed to stop the clamp moving forward by physical means.
The existing clamp tends to ‘migrate’ up the splined driveshaft, putting a constant pressure on the flexplate which in turn pushes the crankshaft into the main thrust bearing. If the clamp is not released on a regular basis (once a year) then the thrust face disintegrates and the crankshaft starts to eat into the main bearing engine web until heat from friction seizes the engine. Dramatic! The Ritech Systems flexclamp sits on the outside of the existing clamp and mechanically holds it so it cannot migrate. The existing clamp then does not need to be checked and released very year. Peace of mind.
