W123, SVO/WVO parts

Another water related question, sort of. While working on tracking down the water leak mentioned in my previous post, I (again) noticed that my wiper blades are uneven be a couple of inches. Is it possible to adjust them to make them more even or is this simply a matter of an aging car? If so, where can I find instructions to make the adjustment? thx. Also - any tips on which maintenance manual/user manual (besides the manuals for sale here, which I will certainly purchase as they seem to get rave reviews) is the best general manual to purchase for working on my new 85 300td??

In adjusting my valves on my 300D nonturbo I am perplexed with an odd occurence. After adjusting a valve to the right gap and tightening the lock nut and adjusting nut, I check the gap again and all is good. But when I use a wrench to spin the valve stem using the two nuts, which turns the valve stem and the spring assembely, the gap changes, even though the nuts are tight. It will get either tighter or looser, but if I keep spinning it it will return to my original adjustment. That is if it gets tighter, by spinning it further it will eventually loosen up.

What is the normal running temp for my 83 300D? Right now it gets hot quickly and moves up above 90C and will approach the 120C point if I run the AC. I've changed thermostats and flush the radiator and put in new coolant along with a water wetter. Seems to run somewhat cooler but not what it should be. The electric fan used to come on but doesn't now. What is the most common thing I should look for if the fan doesn't come on? Thanks, Dan