Re: Rear end piece broke

I have no experience with welding the bottom of that case, but I know from what others have said that it can be done.

Back in the early 50s, a neighbor of ours had an M that lost a bearing and broke out a triangular piece of the casting, much as you describe. It was taken to the local IH dealership, and the mechanic determined that the piece would fit back in the hole almost perfectly. He put the piece in place, and carefully drilled a small hole at each corner of the triangle - right on the crack. He then tapped some threads in to each hole - about 1/4" or so diameter. Then he cleaned the part and the edges of the hole very well, and painted them. Finally, he smeared some Permatex non-hardening gasket sealer on the edges, put the piece in place, and threaded three short bolts into the holes. That M went back to the farm for another 10-15 years and never leaked.