I'm at wits ends with this... It's been suggested that my trans is likely reaching the end of it's life (300,000 miles) and is just wearing out... is this a likely story?

__________________
hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

can you explain how it shifts "all over the map" ???

Does it shift hard, shift early, shift late, or shift randomly such as early and late.

Need more detail

__________________
1982 300sd, new project car to restore

It doesn't matter if you know what you're doing, as long as you look like you know what you're doing.

let me guess, the guy who suggested that is the same person who replaced the vacuum pump? it's possible, but...

if the transmission shifted properly before the swap it should be easy. have a close look at the vacuum lines and make sure they are all connected properly. there are a lot of them on your engine and there are a few that are critical to having the transmission shift properly. my hunch is that in working in the engine bay and fiddling with the vacuum pump, the mechanics have disturbed vacuum lines and all you need is to put them back properly. pay particular attention to #123 on the diagram, and the lines to/from it.

http://i323.photobucket.com/albums/nn447/Jeremy5848/1987%20Mercedes%20300D/Vacuum603.jpg

__________________
________________

punkinfair

The Vac pump Needed replacement, it was leaking oil heavily, I kept it, I'll take a look and make sure they are routed right

__________________
hum.....
1987 300TD 311,000M Stolen. Presumed destroyed