Welding rear end tubes to differential housing

[mrvedit]

After reading larz_quira's story about ruining his differential by spinning the stock non-welded tubes, I am concerned about doing the same thing if/when I try slicks at the track.

Questions - What is the procedure for welding? Just drain oil and weld, or it is even OK to leave oil in?
Gas or MIG welding? Would my Lincoln 135Amp MIG welder be powerful enough?

Thanks for answering such a basic question.

[li0nhart123]

I'd remove the diff cover and drain what you could...have an observer and a hose handy...your welder has more than enough juice to weld the tubes to the housing....i'd also remove the fuel tank to give you more room and to remove the explosion potential.

[gregh]

You need to strip the rear end completely apart to weld the tubes properly. The housing & tubes need to be pre & post heated as well as cleaned to get the welds right.

Some guys think TIG is the only way to do it but I've had great results with a 200amp MIG & using stainless steel(for the high nickle content).

I think a 135amp machine will be a little small for the job.

[theflash]

I don't think this is just a basic question. Did you try the search feature here, since this has been discussed in great detail already?

[big gear head]

http://www.nastyz28.com/forum/showth...g+axle+tube s
Read this first.

The center is made of cast iron and the axle tubes are made of steel. There is only one material that will weld these two metals together, and that is nickel. You can get nickel rods for stick welding and you can get nickel wire for tig or mig welding, but you must do it right or you will not get a good weld. If you use another material for welding cast iron then the weld might look fine, but it will not stick. The surface of the cast iron will break off and the weld will only be on the steel. Welding cast iron is difficult and should be done by someone who knows how to do it right. You are probably going to hear from people who went down to the muffler shop and had them weld the tubed with a mig welder and they will say that theirs has worked fine. That might be true, but they have probably never stressed the rear end enough to turn the tubes anyway. If they ever put enough stress on the tubes then the welds they will fail.

[Doug Jaynes]

Ted,
I used nickle rod for the stick welder, alternating the weld on opposite sides (thats the short version). your 125 mig wont do the trick. BOC gas in A2 has nickle rod and probably the one on Jackson road does as well

Doug

[mrdragster1970]

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If you need it, and going to go through all the trouble, do it right.
The link is a great explanation of the proper procedure.

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[EricsZ28]

Originally Posted by mrdragster1970

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If you need it, and going to go through all the trouble, do it right.
The link is a great explanation of the proper procedure.

.

I actually consulted a metallurgist about this procedure, and he confirmed the write up. He talked me out of going the MIG welder route with the correct wire. His comments were that the MIG welder route with the correct wire may certainly be stronger than stock, but it won't be as strong as when the procedure is done correctly.

I paid about $75 (IIRC) to have a professional welder do this job for me.

[mrvedit]

Originally Posted by theflash

I don't think this is just a basic question. Did you try the search feature here, since this has been discussed in great detail already?

Oops. Shame on me because I sometimes tell others to use the Search function to find detailed threads.

Thank you everyone for all the great feedback, especially Big_Gear_Head for the link to the previous thread. It was late when I posted, I actually do have a TIG welder, but sounds like it would be insufficient especially for a novice welder like me.

[lazr_guira]

If you have a 10 bolt. I would definetly take the time to this. Learn from my mistakes

[theflash]

Originally Posted by mrvedit

Oops. Shame on me because I sometimes tell others to use the Search function to find detailed threads.

Thank you everyone for all the great feedback, especially Big_Gear_Head for the link to the previous thread. It was late when I posted, I actually do have a TIG welder, but sounds like it would be insufficient especially for a novice welder like me.

I didn't mean to come off harsh, but I knew there was a very good thread (posted above) about this on this site somewhere.

[Kevin Callahan]

mrvedit, my brother and I welded our GM 10 bolt diff housing and attempted to document our steps in the NastyZ28 post that BigGearHead linked above.

We happened to use the TIG process, but MIG wire is available for cast iron if you would prefer that process. The essential part for either TIG or MIG is to clean, preheat, and slowly cool the cast iron diff housing. As BigGearHead stated, welding cast iron is not as straightforward as steel.

Further down the post shown above, (in post #9), I list a supplier of Nickel MIG wire: http://www.techalloy.com/. Since I've never MIG welded cast iron, I don't have much advice for the specifics like amperage, wire feed speed and other items like that.

Looking back, the mechanical peening is probably not required, but wrapping it so that it cools slowly is vital to prevent cracks from uneven cooling (i.e. the axle tubes are much thinner than the housing, and therefore stresses the part right at the weld).

[mrvedit]

Thank you everyone for the advice and procedures.

Since it cannot be welded in place, a complete disassembly and removal seems like a huge project. So I have two questions:

* Would it be better to just buy a bare Moser rear end?
Or is a welded 10 bolt stronger?

* And perhaps a really "dumb" question - is it possible to drill holes through the housing and tubes and insert steel dowels?

[big gear head]

A Moser housing is stronger in every way. The axle tubes are thicker, the casting is thicker, the bearing caps are thicker, the bearing cap bolts are larger, the tubes are fully welded...

A welded 10 bolt is stronger than a non welded 10 bolt. You could dowel the tubes, but if you mess up and get the holes even .0005 over size then you're in trouble.

I have a few scrap housings that I used to practice welding on. I tried nickel rods and gave up on it. I've been a DOD aircraft certified TIG welder since '87, so I did a much better job welding them that way. I haven't tried MIG with nickel yet, but it would probably be easier than the rods. I never was very good with nickel rods. They are very different from a 7018 or 6010.

[pdq67]

If I was to go this far, I'd have a built 9" w/ a Detroit Locker instead.

Or a modified Dana 60.

pdq67