welding cast iron

[Ruptured Duck]

I know many of you have done the soa conversion.
So my question is what kind of rod do you use to weld the perch to the cast iron on the diff? My jeep has select trac, so the diff is on the drivers side. So i still have to weld a perch on the diff, right? Any help would be appreciated.

[cjb7804]

If your welding cast to cast, then you want to use nickel rod with an arc welder. Thats the only thing that will burn in correctly and give you the best tensile strenght on the weld. Good luck!

[J20 project]

I think you will find that almost everyone doing this uses 70 series rod through their wire feed. Typically you use a steel perch welded onto it. I agree that in most applications you would use nickel rod for cast to cast but not here. The cast used on the pigs of these is more of a forged piece than the typical sand type casting used for manifolds, etc. If you notice the plug welds holding the axle tubes in are not welded w/ nickel but a higher tensile strength rod. If you do use nickel, be sure and stress relieve it while welding. Wire feeds have tendency to weld cast really well as they don't heat the h#$$ out of the piece. J20

[mandoneer]

a trick I learned a couple of years ago was to bake the cast pieces to get a uniform temp. and then weld and bake it cool - I had shattered an intake welding it,when a buddy told me about this and I havent broken any castings after by doing this - dig a pit light a fire in the pit heat the piece by smother baking it(I.E. cover it with dirt and stuff ), dig it up after about 1/2 hr, restoke your coal pit , weld , recover and leave it for a few hrs. - this might not work so well with a whole axle (because of the size and amount of cleaning you will need to do after and because it might anneal the tubes )but it has worked great for me on intake and exhaust manafolds and other cast items

[2MUD-IN]

A welding buddy of mine said you aren't suppose to weld on cast unless you bake it. He says you CAN weld on it without baking, but it is not a strong weld.

We also found out that there ARE diffs out there that you CAN weld on, like J20 said. You have to research your diff to find out. The front D60 I had we were able to weld on just fine. However, we only needed to weld on it for a bracket, not a suspension item.

[Desert Beast]

i just preheated it w/ a torch, then welded it, then kept the torch on if for a while after. hasnt broken yet.

[J20 project]

Out here in the sticks of Wyo, people like to chase everything from antelope to rabbits on the lone prairie. They had a real tendency to pop the long axle tube loose from their front axles catching a little too much air. The frame and axle shop next door would realign everything and have me come over and weld it up. Never had a comeback. J20
Oh, and I stick welded them w/ 7018DC.

[Ruptured Duck]

Thanks for all your help!

[kyjman]

Being as the diff is cast steel, and not cast iron you can weld those on with a 70 series low hydrogen rod after a pre-heat, and a slow cooling down period. They will hold if done with the correct welding procedure.