I have two ETA movements in pieces on my desk right now. Both needed service after I was a lazy idiot and used a pin instead of a screwdriver to get the stem out.
One is an ETA 2836-2 with GMT instead of day/date. I got it apart and back together and I thought I had all the keyless stuff in the right place. However, when I install the stem and try to set the time, it seems like some gears aren't engaging fully. I get a crunchy noise when I turn the stem one way, it slips when I turn it the other way. In one click seems to turn the date and GMT wheel, but with the strange noises I wasn't going to play too much with it.
The other movement is also an ETA 2836 but without day or date wheels. It had the same problem, and I got it apart and back together without issue, but it no longer handwinds. It hacks, the datewheel turns in the first position, and the hands adjust in the second position, but in the fully-in position it will not handwind.
I desperately need a picture of a 2836 taken apart, so that I can be sure that I've got everything back where it goes. I found the flash tutorial of the 2892 and it's been really helpful, but it's not exactly the same.