I'm trying to get my truck ready for it's out of country inspection. I'm no stranger to removing a brake drum, or working on brakes...and I've been able to get the drums off every vehicle I've ever owned. Until now. The shop manual says to loosen off the adjusting wheel, and simply pull the drum off. The adjusting wheel doesnt seem to turn, and I cannot get the drum off at all.

The brakes work very well and are smooth and quiet, but I'd like to make sure anyway.

Any pointers as to what I'm doing wrong?