Well I decided to sell my 87 300SDL and everthing seemed to be working fine. So the first guy that comes to take a look takes it for a test drive, and guess what - about half way through the drive it stops upshifting from first gear.
At first he could get it to shift, but now it won't get out of first gear for anything.
I have read some about the modulator vacuum line and fluid levels. Does this sound like a vacuum problem or something more serious with the transmission.
Thanks for any help.