I actually have two questions about my 1984 W123 300 D turbodiesel.

1.) I replaced the Thermostat (the new one is rated at 80 degrees Celsius) in the car because my engine was only running at at 70 degrees celsius. Now my car is running at 90-93 degrees when the air is blowing cold and at about 80-85 degrees if the air is blowing hot. Is that normal? Do I need to be concerned about the 90 degree plus reading on my dash board when I use cold air?
2.) My second question is that my car was actually shifting just perfectly fine but, being new to the figuring out the mechanics of the engine and because I was fiddling, I must have messed it up. This what I did. Upon recommendation of a fellow Mercedes friend, I sprayed some teflon into the transmission Boyden cable. I also reconnected each of the vacuum lines into their respective rubber fittings one vacuum line at a time. Then I decreased the tension of the transmission Boyden cabel. But I didn't look carefully at how far the adhjustment screw was turned in when I started. After fiddling with the right tension of the cable, my car now shifts from 1st to 2nd gear at 2400 rpm, 2nd to 3rd gear at 2400 rpm also and then from 3rd to 4tgh gear at about 2900-3000rpm. I don't mind that but when I slow down the car and get down to 900-1000 rpm, there is a pretty noticable clunk into a low gear. The car used to not shift down this rough. What did I do wrong? Could this be caused by the Boyden cable or could it be a vacuum problem. Any insight would be appreciated. Thank you very much, Detlef