Duffer, could you send a pic please.

 

The housings are cast STEEL not cast iron as many point out, so it's possible to weld it..

I wonder if Harry is thinking of JB Weld. If the hole is small, and you can get ALL of the oil and grease cleaned off of it, you should have a decent shot at fixing it with JB Weld. So long as you:

1. Clean it extremely well.
2. Get a NEW tube of JB.
3. Mix the JB thoroughly
4. After applying it, give it the FULL 24 hours to setup and harden before you do anything to it..

Every time I have short cut the steps I have had poor results, but when I do it right and give it time, I've got bearings and shafts being held in place for years with that stuff.

OR, you could swap the rear end.. My son and I have been collecting parts tractors and at last look we have 3 complete 4xx rear ends in the barn. We are located in Central Illinois right at the confluence of I-55, I-74 & I-39

 

Bronze it. Easier than welding once you "cook" it a couple of times to bring out the impregnated oil.

 

It actually welds quite well. We use a plate of mild steel a good amount larger than the damaged area and weld around the perimeter. That avoids chasing cracks in the cast steel housing as well as the issue of oil contamination due to the porosity of the cast steel. It works fine as it is not structural; you're just trying to keep the oil inside.

Bob

 

Everyone has terrific ideas. I thought a pic would give ideas for a plan to repair.