I have a Bell & Howell Autoload 245BA 8mm film projector. The bottom sprocket wheel does not turn and the film stops loading there. I can turn it manually with great effort. I've taken the cover off and tried some 3-in-1 oil, but it still doesn't turn on its own. The metal bar on the backside just skips across the plastic gear wheels which do turn properly. Any ideas?

Eugene, June 2014