Can cast iron axle be welded?

I use the tractor everyday, so obviously, it's not that much of a problem, but I'd still like to have it fixed to where there is no drip at all. The epoxies like JB Weld are not working. The oil eventually seeps through even after draining the rear end, throughly cleaning the surfaces, and letting it dry.

Although it's not causing me much grief, it's one of those things that sits in the back of my mind and just bugs me. Is it possible to weld this?

You'll be money and grief ahead if you find another way to fix it, or possibly replace it. The fact that JB Weld is failing in spite of your apparent correct application tells me that the part is under some stress. There are industrial adhesives/fillers, more flexible than JB Weld, that may work. Look up "industrial supply" in a big city phone book. They may be able to steer you to a product that will work in that application.

If you were to completely dismantle the rear and, and bake it for a number of hours to burn all the oil out of the cast iron, it could be sccessfully brazed or welded with cast iron or nickel rod while still hot, and then allowed to cool down slowly to prevent stress cracking. The old blacksmith in our area used to bury welded cast pieces in hot ashes from a wood fire, and allow them to slowly cool along with the hot ashes. Another way is to wrap the just-welded piece in glass wool insulation to prevent fast cooldown.

How to bake the casting? Some use an old kitchen oven (Hopefully not the Wife's!) to heat the casting to 400-500 degrees for several hours. Some up-to-date automotive machine shops use an industrial oven to burn the crud off of engine blocks before rebuilding. Perhaps there is one in your area.

Arc welding the casting takes a certain amount of experience, although it is not that hard to do. However, with a one-of-a-kind part such as this, it might be a poor choice of a part to experiment on!

The alternative would be to bake the part clean of oil, clean and roughen up the area around the damage with coarse emery cloth, and then epoxy it, possibly putting a metal patch over the damaged area. If done in this manner, I doubt you would ever again have trouble with a leak through the epoxy, and, in fact, this may be the best fix.

CJ

Lacking these, you can also weld it without preheating if you weld about a half inch, wait till it cools to the touch, and weld another half inch.

In any case, use a sand or lime box, or some other method to keep drafts away from the piece and retain the heat so it will cool slowly.