The following pics and description were recently posted on fordbarn.com by Tom Wesenberg. Thanks for his permission to post them here, too!
Someone asked me yesterday how the armature was supported at the rear since the shaft ends at the commutator and no bearing support is visible. Here you can see the case extends well inside the armature, which has a deep hollow center.
The shaft is supported by 2 good sized bearings. The larger one on the pulley end is a 204 and the armature end is a 203 bearing. With the large cavity to hold grease I have yet to see these bearings fail in a manner that would leave someone stranded.
After cleaning the original bearings, some may have a slight click as it's spun. In that case I'll install a new sealed bearing. The click is so slight that I'd bet the bearing would last my lifetime with new grease, but as long as it's apart for under $10 It's best to just use new bearings.
Tom Wesenberg