Welding axle truss to diff?

Farm Boy

Farm Boy

Bought the Farm
I'm in the process of building a truss/upper link mount for my 14B and looking for input into welding it to the cast diff. Currently cut to fit the profile of the diff (gaps are a bit bigger than I'd like) but considering cutting out the coped profile and just boxing it in so that it only welds to the axle tubes themselves.
I'll also have a BFT pinion guard that will bolt to the front of the truss for more support.

Opinions?

I will also be shaving the bottom of the diff 2 or 2.5" and...
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mucovich

mucovich

Till Valhalla!
I've read that the biggest one is to preheat the metal before welding, and I also remember something about using rod that has more copper? content (I could be wrong on that one and I don't remember it being too important). I do know that alot of dudes just weld it normally to the center section (like me) without any problems. The welds will be ugly though when welding to cast like that.
 
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Dirk

Guest
high Nickel rod. Any welding shop can sell you the right rod, just tell them what you are doing. They are expensive rods tho...be prepared, like $6 each.
Check with Dwayne as to which he used.

On the other hand....preheat the cast....weld with regular rod or Mig.....you will probably never break it anyway. This is what I would do.
 
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Dirk

Guest
rosebud on a oxy-acetelyn torch.
maybe a big propane torch, like the ones used in construction to heat before installin bituminous membranes....or maybe point a big construction heater at it wile its on stands. :clue:
 
blueguy

blueguy

Jackstand Racer
When I welded Scotty B's brackets onto his HP60 and 14B, I just MIGd the brackets that were attached to the cast. The pig got heated with a handheld propane torch for about 15mins in the area the weld was to be, I burnt in the bracket, and we covered it with a blanket to let it cool. It wasn't necessarily the "best" way, but it worked and from what I understand, the bracket is being beat on regularily out East and holding up :D

BTW, I'm pretty sure I saw nickel rods at PA. Might be another choice for less-than-$6 a rod....
 
Mitko

Mitko

The G-Spot
Club Member
blueguy said:
The pig got heated with a handheld propane torch for about 15mins in the area the weld was to be, I burnt in the bracket, and we covered it with a blanket to let it cool.
Click to expand...
This is the proper procedure - preheat, weld, cool. Slow cooling is as important as preheating.
 
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Root Moose

Guest
Is the housing nodular iron or cast steel?

If nodular iron you need to pay attention to the heating and cooling cycles. IIRC heat to 450? and keep it there. Then weld with whatever process you are comfortable with. For stick use a high nickel rod like mentioned above. Use a welding blanket to ensure the piece cools slowly.

If cast steel just weld it and be happy.

At least that is my understanding.

When I trussed my thirty I was uncertain (hey - I'm just a shade tree mechanic) so I did the heat/cool process. When I do another one I'll find out what is specifically needed for the axle in front of me.
 
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Root Moose

Guest
Oh, and obviously with this kind of heat, empty the differential before welding. :)
 
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Root Moose

Guest
It depends on what colour the sparks are when you touch a grinder to it. If yellow then steel, if orange then iron - or maybe I have it backwards. A quick google should confirm it one way of the other.
 
Cochise

Cochise

Well-known member
Orange or red is definitely iron.

I run iron powder in some of my rocket motors specifically to get a red flame.

Steel: yellow, cast: dull red sparks.

[edit]: I checked just in case burning is different than grinding:

http://www.tpub.com/content/armyordnance/Od1643/Od16430038.htm

Another way to check is drilling: cast makes crumbly bits, steel will get you corkscrew stringers.
 
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