This was the first issue I chose to address on my 1945 Pacemaker. When being moved to its long stint outside, it was placed on a pallet. Naturally, the garden variety pallet could not support the 8000lb brute and it tipped forward into the mast of the forklift, or so I am told.
Anyway, here's a pic of the z-axis handwheel:
First, I wanted to remove the cracked casting**. The handwheel was the first thing to remove. Then, four socket head cap screws needed to be removed and then some gentle prying and tapping to free the casting from the apron. There is a dowel at the bottom that needs to be freed. Once its clear, it should slide right off.
There is a sealed ball bearing installed in this casting. On my lathe, this bearing had seized and worn a groove in the shaft, so it was slated for replacement.
To remove the bent shaft, a nut on the backside of the apron must be removed. There is a lock ring which fits in a miniature keyway on the shaft with a tab that catches the nut. Not sure what the techincal name is for these, but you see them on cars occasionally too. Anyway, if you can get back behind the apron with a screwdriver and then a pair of pliers to get the lock ring free and the nut off your better than I am! I opted to remove the carriage and apron.
To do that, you must first remove the leadscrew/feed rod/clutch rod support. I first removed the caps on either side of the feed rod support to see what was going on in there. The clutch rod and leadscrew just float in brass bushings so no trouble there. Next I removed all the socket head cap screws securing the support to the bed. I suspect there are a few other ways to remove this but I went about it by rocking the whole support back and forwards a bit to loosen the dowel and then removed the dowel. This allowed me to slide the support off from one end.
**Note that this isn't really the best time to do this, since I opted to remove the apron in order to free the shaft. To do that, it requires that the carriage be moved by the handwheel. In this case, it didn't matter too much since the shaft was already bent and damaged.