Used trans installed in 75 300D issues..
 

After 2 months in the shop the 4th transmission sent was finally a correct unit and is now installed though it's hardly shifting properly at all. (This is what I get for letting the mechanic talk me out of buying a professionally rebuilt transmission and installing it..)

But there are the further issues that have now come up. The automatic glow plug is not not working when you turn the key, the fresh air vents no longer function and what concerns me most is the engine oil pressure has fallen to nearly half of what it should read though the fuel mileage is about 30mpg.

Is it possible that any-all of these new problems can result from a faulty transmission installation?

The trans functions but will not shift unless you take your foot off the accelerator. The mechanic assures me this is just temporary which of course I doubt very much.

Any thoughts?

Was the engine removed to replace the transmission?

It sounds like the electrical and the vaccum was meddled with and or improperly reconnected when the transmission was reinstalled which is not surprising since the mechanic has done it 4 times and is probably pretty irritated.

I'm going to start a new subject on this matter, any input will be appreciated.