1991 190E reverse problem
 

My MBZ just started doing a strange thinge. Reverse works so long as I'm on level ground. If i have to go even slightly uphill, the engine revs, just like it is in neutral. I check the tranny fluid and it's level, and both are OK. Is there some sort of vacuum line involved with the transmission?

Perhaps a blown seal on the reverse piston - not a huge job except that the transmission has to come out, and once you take the transmission out you might as well rebuild it.

If the seal was blown on the reverse piston, wouldn't reverse not work at all? On level ground reverse does work, although it doesn't have full power. Any idea what a rebuild of the tranny would cost? Since I'm in the San Francisco Bay Area, I'm thinking it is going to be REALLY expensive!

A small breach in the seal could still allow reverse to engage under certain conditions. The other thing it could be is the reverse clutchs worn. Do a search - there's a number of threads on reverse won't engage and lots of information. The way to avoid San Fran. labor cost, at least partially, is to get a rebuilt unit shipped in. Should be about $1200 from Sun Valley http://www.mercedesdismantlers.com , plus freight plus about six hours to R and R. There's also some information in the archives on repairing just the reverse seals and clutches - it's the first thing you come to when digging into the transmission. Again, the R and R is the big deal.

Thanks Deanyel, I'll do some searching in the forums about the seals and clutches, and then decide what to do. Sounds like getting a rebuit is the smart way to go, though.