Valve Clatter

[George M]

I rev mine all the time in Park...lol. Am challenging the trans to blow so I can install a Getrag 5 speed. Not really. If the A-clutch input shaft seal is worn, then you can overpressurize the A-clutch in Neutral or Park only if the car was been put in drive just before. After a long cool down or after initial start up, you can rev the engine in P or N without incident. The fix is to replace the steel O-ring with a Teflon seal. Winfred has a superb write up on the procedure as he has done a lot of them.
George

[Dick Schneiders]

The later ZF's and the GM auto trannys on the 525's should not be a problem

If I remember correctly, you SHOULD NOT rev an automatic E34. I believe there is a weakness in a seal in the tranny. Revving the engine while the transmission is in park can blow this seal out. Bad news I'm sure. Bill R may be able to back me up on this, but after I read it, I never, ever rev mine while in park. I don't even like to think of a rebuild or buying a new tranny.

Grace and peace,

Robert K
1991 535i

[George M]

All E-34's and E-32's with ZF 4HP 22 EH and M-30 engine through 1992 had this issue.
George