First , do you have one of those new 9 bladed fans on your engine ? If not I suggest putting that on quick,,,, about $36 dollars I think...

Second, lets don't use the phrase " tearing into"...lets say " carefully disassembling " .

Those guys were just not interested in messing with it because they make more money selling their own stuff... MOST BEARINGS HAVE BEEN METRIC FOR 20 years....

Get to the library before you take it apart... so you know what to look for with respect to brushes if it has them... and take lots of pictures as you open it up.. another person taking the pics would be ideal... When you get it open post the pics... put a couple of drops on the shaft and leave over night in a position where it will drain onto the bushing.. do it for each end since you don't know which is binding...

See if you can find a copy of " How To Fix Damn Near Anything " it is a great book because it also deals with diagnostic philosophy and methods... and has a great section on electric motors as well... Greg

I edited this to show the correct number of blades for the new engine fans..... 9 !