I've tried everything but Joel's approach (and William's the drilling suggestion) and wonder it a standard acetylene (propane) torch is hot enough to weld a bolt to the steel bearing. I assume I'll lose the aluminum bonnet hinge (as a result of the heat necessary to make a permanent weld), but that's replaceable.
Another thought would be to use a 4" disk grinder to "square off" 2 sides of the steel bearing, then use my 15" spanner wrench to try to break it loose. I'd have to cut the aluminum hinge off first to give the wrench access to the flats created.
Comments?
Many thanks.