I had my 1988 E32 tranny rebuilt some years ago with good results for < $3000. Not the same auto box though. Just sold that car yesterday! 200K + mi. one owner DIY car. On the old E32 forum board at bimmerboard there was a go to guy at ZF here in the USA >>> Contact Kurt Kellar in Zeeland, Michigan. He's busy, but if you leave him a message with a phone number he will call you back. Great guy and an expert on these transmissions. His number is 616-748-5735. I would bounce all of this off of him,ie. rebuild yours, exchange, etc. BTW, I have (2) two new, unused (in the box) rear shocks for a coil sprung iT if you need them (or anyone else).