Starter Bendix?
 

Car is 1975 240D, 4-speed manual transmission, 4 cylinder.
Northwest Ohio just started getting cold overnight (mid 30's), and this problem just popped up. Car lives outdoors, have not started using block heater yet. Currently have 15w40, planning on changing this weekend to a syn 5w40 for the winter.
Problem is this: yesterday morning and this morning after glowing the plugs, when I pulled the gorilla knob out to engage starter, nothing. No clicks, no noise whatsoever. So I pushed it back in, turned the key off, then back on, unbuckled and rebuckled my seatbelt, jiggled the stickshift, engaged the clutch a couple of times, threw salt over my left shoulder, then started over again with the glowing, and she started fine. She once, several weeks ago when starting her, made a grinding sound when starting her that sounded like when you attempt to turn on a gasser that is already running (grinding starter sound). I let go, tried again and she started up fine.
So after some reading, this sounds like a sticky "bendix" in the starter that has worsened due to the cold weather thickening the grease????
Is this right, and how do I go about fixing this problem, apart from building a heated garage? I have seen some mention of taking it apart and cleaning/re-lubing it, but didn't see any details and wonder how difficult this is. Thanks, Alex

Check that ALL electrical connections are clean and tight, including ground strap (from body to transmission on my 300 TDs).

A broken bendix spring will result in the starter spinning with no load - a load high pitched noise. You would definitely have heard that. The grinder noise you heard earlier maybe, but not the case where you hear nothing.

I'm going through a similar issue and there are several things that could cause it (iginition switch, starter relay, bad cable connections, battery going bad, sticking GP relay,...) that all you can do is test one at a time until you catch the problem.