190D 2.5 turbo trans problems

[simwilldig]

I have a 87 2.5 turbo diesel that has been giving me trans problems. I bought the car two and a half years ago showing about 146K miles (actual about 170K). I've put on about 45K. It has always shifted hard. I had the fluid and filter changed shortly after I bought it.

Problem #1
Last winter I started noticing the trans slipping starting out from a stop when the trans was cold. If I shifted down into L before starting it would not slip. I never noticed any slipping in other gears. When starting out from a stop in reverse, I never noticed any slipping either. It still does this, but only when the trans is cold and has not seemed to get any worse.

Problem #2
Two days ago when my wife was driving it, it had a fit of sticking in each gear. That is, it would not up shift till 3000-4000 rpms and even then hesitated to shift. I drove it then and it did it for a little, but after giving it full throttle and letting off to make it shift, it started shifting like it normally does. Yesterday and to day I drove it and it seems to be normal.

I just unhooked the vac line running to the modulator valve on the side of the transmission and drove it around the block and it hammered into each gear very with out slipping.

My question is, Do these sound like vacuum problems, or is my trans need to be rebuilt? Any ideas as to what might be causing the slipping while cold, or the random shifting problem?

Another question, it clunks pretty bad when downshifting. Is there a way to fix that?
Any ideas or input would be great!