Rebuilt transmission source
 

Anyone know a good source for a rebuilt automatic transmission for a 1985 928S, US?
Mine is slipping in first, and I want to research a replacement if necessary.

I have reached out to both of these companies, but have not heard back from them:

Rebuilt Transmissions - Remanufactured Auto Transmissions - Automatic Transmisions

Master Tech Transmission - Contact Us

I think it's a Mercedes trans so you should be able to find many shops that can work on them. Have you contacted any of your local places?

Mastertech is the expert. Steve Cataneo. Long-time rennlister, 928 owner and mercedes trans expert. Find the phone number and call him.
That's where I'd go if I could afford anybody else working on it.
He knows their weakneses, strengths and what parts were supersceded to improve them as they were produced.

Serious bucks to rebuild, and "most" used ones are fine, they don't wear out, they only get abused out. $500 should get you a known good used transmission, rebuild exchange more like $2k.

I would not trust a rebuild to anybody that doesn't do a lot of them. Many a sad tale from owners who went to a well known quality local shop, and went back, and went back, and then sent tranny out as a core.