dkh
I had a similar problem on my 51 3/4 ton. The brake shoes had worn the drums enough that there was a small ridge on the inside edge of the drum and the shoes were frozen against the drum, so when I tried to pull the drum off the shoes were catching on the ridge and I couldn't get the drum off.
I'm not sure if your set-up is the same, but I unbolted the wheel cylinder from the backing plate and then, using a screwdriver through the bolt hole, knocked the wheel cylinder into the drum. This released the shoes enough to get the drum off.
Good Luck!
