GM 12 bolt rear end Question

[Kubs]

I have an old GM 12 bolt rear end that I'm considering revising and fabricating to fit my car (GM F-body). However, I'm not 100% sure what material the differential housing is made of. I've searched the internet and all I could find was the bearings caps are cast iron but that doesn't tell me anything about the actual housing itself. Anyone have any insight on it? If it's cast iron I'm prolly not gonna mess with it, which I'm thinking it is.

[MarkBall2]

Center section (where the ring gear/pinion are held) is cast iron. However, that differential housing can be modified if you can weld. Just takes some preheat & rosette welds, then cool slowly.

Do a search for offroad truck differential modifications. Most of those guys use MIG welders to weld the axle tubes to it. Axle tubes are generally DOM steel & easily welded.

All that said, if you don't have confidence in your welding abilities, you may be able to find someone locally that could do it for you, if all you did is tack weld to the proper angles.

Good luck

[lewray]

Some are nodular iron, but should not make a diff.

Question is What exactly are you planning on? Obviously you are going to weld some brackets to it?

Let me know.. Good luck

[Kubs]

I haven't done anything yet. Just considering it for now. Everything on the 5 link setup pretty much just welds to the axle tubings but the torque arm pretty much needs a mounting spot on the center section. I don't feel 100% comfortable with welding to cast iron. I might have to find something of some scrap to play with and practice on first. Might have to revisit this later I suppose. I don't have a real need for it as I already have a Moser 12 bolt in the car. But figure it would be a nice lil project and one of my more useful ones too

Lewray,
I need to mount some torque arm brackets to it. As I said previously I have a moser 12 bolt already and this was just gonna be a lil project since I have it but I don't exactly wanna go in blind and fail as its not exactly a useless item. My Moser is fine, but it would be great to have a through bolt design like I believe strange has on theirs and what comes stock on the 10 bolts for the F-bodies. Moser's have a tendency for bolts backing off, particularly the top. Locktite and torquing them down doesn't trump checking them often I'm afraid.

[lewray]

Originally Posted by Kubs

I haven't done anything yet. Just considering it for now. Everything on the 5 link setup pretty much just welds to the axle tubings but the torque arm pretty much needs a mounting spot on the center section. I don't feel 100% comfortable with welding to cast iron. I might have to find something of some scrap to play with and practice on first. Might have to revisit this later I suppose. I don't have a real need for it as I already have a Moser 12 bolt in the car. But figure it would be a nice lil project and one of my more useful ones too