Don Terrill’s Speed-Talk

What welding rod or wire should I use to weld the axle tubes to the center section on a GM rear. I have 3 options on welding, regular stick welding, MIG or flux core wire. Dan

If you were being technical I guess it would depend on whether the centre section is Grey Iron or Nodular

But regardless a decent high Ni rod will get it done, and with the cost of such it would be most economical just to buy a few rods, so stick

Good clean up prior, a nominal pre-heat and peen as you go wouldn't hurt the job either

Get the all lube out the axle first ..... it stinks to high heaven when welding

Thanks, BCjohnny. Not sure of the material. It's a GM 8.5" 10 bolt from 1972 out of my Camaro. I do have 4 or 5 hi nickel sticks left from another project. Dan

I would check but the center may be cast steel. On Ford 8.8, I usually tig them but have used mig also. Whatever was available at the time. I was told that the Ford 8.8 is cast steel. I've never had one crack.

fordified wrote: ...... I was told that the Ford 8.8 is cast steel. I've never had one crack ......

Not wanting to pick an argument, but that's highly unlikely

True cast steels are used less and less today, due to cost and being a production managers nightmare compared to the developed alternatives

Throughout industry they've mostly been replaced with malleable, or more recently ductile (nodular) cast irons, with ADI increasingly taking up a bigger share of the higher duty stuff

Regarding axles, the 8.8 I'd suggest would be nodular, a lot of manufacturers have on the whole transitioned from GI to N over the years where required ..... Dana for instance quoted using it extensively for centre sections

In the 'adequate' & 'cheap' curve it generally hits the sweet spot

You're probably right about the old GM stuff, but I've been told many times the ford is cast steel. I've never checked but welded probably a dozen of them and never had a crack using either mig or tig.

If the GM is nodular, then nickel would be my preference. You can get nickel-iron mig wire. Put some heat in the casting and weld smaller beads alternating between top, bottom and sides and peen each bead right after you weld it.

You could also braze it or tig it with aluminum bronze rod which would be cheaper and easier. You'd be surprised how strong braze can be.

I know this thread is older but I will put this in as what I have used in the past welding tubes in on GM rear axles. I always use Muggy weld and it works great for welding steel to cast parts. Just look it up on line. I also noticed I can make the stick portion of my Tig welder make better use of this rod over my old Lincoln welder. Worked out great and I have another 8.5 to do. When I weld that one I will post pictures.