My 300sel takes a good 4-6 seconds to engage reverse too. With nearly 300k, it's days are limited. PO had it resealed, which is good... but why they didn't go thru it at the time is beyond me. My mistreated SD and SDL still take up reverse quick.
PM me and I'll mail you the factory manual on the 722.3 It's not a super complex trans by any means, you'll see when you check the PDF
Rev clutch pack is behind the 3rd gear pack and the B1 band. So if you wanna do it quick, just replace those two clutch packs, reseal it, and drive on.
Buy your kit from bulkpart.com Install the shift kit from Superior trans to clean up all the up and down shifts.
A cat I know rebuilds the ZF trans in my BMWs, he may do the 722.3, I'll have to ask him if you're serious. The FULL REMAN on the ZF isn't even $1k.
Change your rear main while in there!
