I'm looking to sell my 87 300D, and I've been spending a lot of time fixing it up. For the most part, it is a pretty strong car. However, I've been noticing some transmission oddities:

1) Sometimes, when I go from drive, to reverse, and back to drive and accelerate to some small speed and then coast, I hear a loud snap, almost as if two metal plates were slapped up against eachother. I took it to the indy once, and they couldn't reproduce the sound. What could this be?

2) I think the trans' shifts are off. If I accelerate a little (say to 10 or 15 MPH) and then suddenly let go of the acc. pedal, the rear seems to make a clunk and the car lurches a little. I think what is happening is that it is shifting into second really early, and then when I stop accelerating, it shifts back into first. I think it should just be in first the whole time or something.

3) Sometimes, before I can get into third and fourth gear, I have to let off the pedal a little bit.

Are any of these problems vacuum related? Does my rear diff. need a fluid change (it hasn't had one in forever)? Is trans on its last legs? I've been driving it for a year and a half with most of these problems, and the car still performs pretty well, so I'm hesitant to think that the trans is about to go out. Any and all suggestions are welcome!

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1987 300D wvo on the way!