Welding axle tubes

[Quickboat]

Is the housing of a GM 12 bolt differential cast steel or cast iron? When welding up the axle tubes can they be migged without special wire?

[Todd in Vancouver]

I would contact one of the rear diff specialty guys/companies and get a definite clarification . My understanding was that you can't weld to the GM housings and that's why the suspension companies offer the cradle looking set ups that bolt to 12 bolts rather than tabs to weld. Maybe they were just trying to make it easy for guys like me as I am going with the TCI rear 12 bolt set up.

http://www.totalcostinvolved.com/pdf/cat/TCI_pg09-10.pdf

[badazz81z28]

I had my axle housings welded to the pumpkin. I have a 10 bolt, but same as the 12 bolt. The housing is cast iron and the axle tubes are steel. You need someone with some skills! They need to use pure nickel rods to do it. The metal needs to be pre-heated and cooled slowly. Any other rod will look good but not be structurally sound.

[carguykeith]

^ What he said, except not all Nickle I used 90% Nickle and stick welded it. To my knowledge MIG is a no go, either TIG or stick with Nickle.

https://static1.pt-content.com/images/pt/2012/04/41211362826-1.jpg

[gotyorgoat]

There was just an episode of Muscle Car on Spike where he modified a 12-bolt. They make everything look so easy. Link below.

http://www.powerblocktv.com/episodes/MC2013-07

[badazz81z28]

A well respected guy that builds rear ends told me about the pure nickel requirement. Not sure how important it is going 90% or pure.

[Quickboat]

There was just an episode of Muscle Car on Spike where he modified a 12-bolt. They make everything look so easy. Link below.

http://www.powerblocktv.com/episodes/MC2013-07

Thanks for the link....I was looking for that.

[KnightMare]

Yeah I was watching it too. They made it look too easy. I've seen a couple of guys at school tig and mig weld housing without problems

[Quickboat]

Yeah I was watching it too. They made it look too easy. I've seen a couple of guys at school tig and mig weld housing without problems

As my welding forman said, he would be very surprized that GM would use cast iron over cast steel. Cast iron is pretty weak and brittle for the pumkin.

[rohrt]

There was just an episode of Muscle Car on Spike where he modified a 12-bolt. They make everything look so easy. Link below.

http://www.powerblocktv.com/episodes/MC2013-07

That was a very good video. He made it look easy.

[Kenova]

Is the housing of a GM 12 bolt differential cast steel or cast iron?

I have been told you can find out with a drill.
If the drill leaves a pile of dust then it is cast iron.
If the drill leaves actual shavings then it's cast steel.
Like I said, this is something I have been told and haven't had an opportunity to try it. If somebody can shine some more light on it that would be great.

Ken

[Quickboat]

I have been told you can find out with a drill.
If the drill leaves a pile of dust then it is cast iron.
If the drill leaves actual shavings then it's cast steel.
Like I said, this is something I have been told and haven't had an opportunity to try it. If somebody can shine some more light on it that would be great.

Ken
That is a great idea Ken, I have the brackets I cut off to experiment with...

[SShep71]

A easy way to tell the difference between steel and castiron is the spot check with the TIG and a file. If you spot it quck and file the "spot" after if it files easy its steel. If it doesnt file easy and acts as if it is hardened it is cast. As others have said, HIGH nickel wire with a few pre/post heat cycles. Watch for imperfections, and coldlaping and undercutting. The effects of both are intensified on disimilar metals.

[Quickboat]

I ran the "chip" test and this stuff does chip. But it is cast since when we welded a sample to a steel plate and hammered it to see if it bent or broke, it snapped like cast.

[tommycomfort]

I've been researching this topic for over a month and had planned to weld mine in my welding class with high nickel wire. But, we didn't have the correct wire and it was fairly expensive to buy for just doing the rearend. TIG was an option, but I really don't feel comfortable enough yet with TIG. So, I found a local chassis shop that welded up both axles (and touched up my swaybar mounts) for $30. Can't beat that!

Also, all my credible research showed that 10 and 12 bolt housings are cast steel.

[woody80z28]

The local welder that did mine said you could tell by the color of the sparks when grinding on it. He stick welded it.

[Bad94]

If you weld the tubes to the center you need to pre heat and post heat. Bring the rear end up to heat, weld and then keep heat in it and slowly bring the heat down. We welded my tubes and when we narrowed my housing.

72750


Tig welded with a special rod.

[KnightMare]

I've been researching this topic for over a month and had planned to weld mine in my welding class with high nickel wire. But, we didn't have the correct wire and it was fairly expensive to buy for just doing the rearend. TIG was an option, but I really don't feel comfortable enough yet with TIG. So, I found a local chassis shop that welded up both axles (and touched up my swaybar mounts) for $30. Can't beat that!

Also, all my credible research showed that 10 and 12 bolt housings are cast steel.

That's what I plan on doing... Or just have moser do it for me when I get a new rear lol

[badazz81z28]

If you weld the tubes to the center you need to pre heat and post heat. Bring the rear end up to heat, weld and then keep heat in it and slowly bring the heat down. We welded my tubes and when we narrowed my housing.

72750


Tig welded with a special rod.

You are correct, any shop who would do the job for $30 did a poor job. It may look good visually, but not structurally solid. To do this job right, its a few hours of labor. You need to pre-heat the rear end for penetration, weld it, and slow cool it to prevent the nickel from cracking. I'm pretty darn positive, all GM 10 and 12 bolt housing are CAST IRON not steel.

It cost me $220 to have my rear end welded. Took the guy about 4 hours to do it. It was wrapped in insulation for a day to cool.


Read This: http://www.nastyz28.com/forum/showthread.php?t=18890

[tommycomfort]

You are correct, any shop who would do the job for $30 did a poor job. It may look good visually, but not structurally solid. To do this job right, its a few hours of labor.

Now Rob,
This isn't my first rodeo and making that statement without more information is just foolish.
Tom

[Quickboat]

My guy is going to tig it with nickle rod. He has some rod so I dont have to buy but what is used. I just hope he heats it and cools it properly. His welding skills I have no doubt about, it is his patience after it is welded, wrapping it up with insulation and such that I hope is the same.

[badazz81z28]

Now Rob,
This isn't my first rodeo and making that statement without more information is just foolish.
Tom

The nickel alone is more than $30. I just don't want to see a guy take his ride to the local muffler shop and find out the hard way it didn't penetrate.