A few welding questions for Purejeep Truss and Gusset kit

JakeMate

Well-Known Member
Joined
Jul 19, 2010
Location
Waxhaw, NC
A couple questions:

I'm thinking of getting the Purejeep Backbone Truss and C-spine gusset kit for my 2012 JKU Rubicon and I'm a new welder.

  1. I believe the backbone truss is 3/16" steel. What is the thickness of the axle tube? Just trying to figure out a starting point for the welder settings.
  2. In both pictures, there are a few tight spots that I can foresee will be difficult to prep the metal for welding. Other than a 4 1/2 angle grinder with a flap wheel, what are you guys using for getting into some of the tight spaces? Mainly on the differential housing for the truss and those inner surfaces for the c-spine gusset.


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What kind of welder do you have?

I typically use a pistol grinder with a 2" pad on it.
 
It's a Hobart Handler 210MVP. My buddy has one of those pistol grip jobbers. I've used it before and it works pretty well. I'll have to ask him where he got it. Some others have suggested a wire wheel on the angle grinder also.
 
pending on what your welding a wire wheel seems to smear certain coatings and definately oils. Also if its brass or stainless steel you can get small amounts of contamination in the metal. Worst cheap ones fly to pieces and are dangerous. I leave wire wheels for heavy rust. Small cracks and crevices get a rough di grinder bit or even apick if its critical welding. I also like a 90 die grinder with a roll lock attachment with 36 or 60 ish grit 2 inch disk. They don't clog easy and don't waste time polishing instead of cleaning the surface.
 
Yea and to add to what warrior said. Wire wheels around inner c's, shock mounts and lower link mounts tend to bring the hurt. 2" Roloc's on a right andle die grinder are the way to go in tight spots.
Does that truss go all the way across the axle or just the pass side? If it goes all the way across you may even want to pass on welding to the diff any more than you have too.
 
Don't weld the truss to the diff all at once, weld small sections and let it cool off. I've seen a weld crack on the diff (that was welded all at once) about 5 minutes after it was welded. Welding small sections at a time will hopefully keep it from getting too hot. You might can also try pre-heating and post-heating with a torch, but unless you are pulling the axle apart to weld the truss on I wouldn't reccomend that.
 
Thanks for the replies guys. To answer MarsFabs' question, the truss is on both sides of the diff, but they're separate pieces so it does have to get welded to the differential housing.
 
wire welder? Man, use a 6011 and don't worry about the paint or oils, that rod will burn right through that crap! Maybe then cap with a 6010 or 7018 to make it pretty :D
 
That 6011 wont work well on the cast housing. Clean it if your gonna stick it run a 7018 & skip around with the weld. ping it between welds.
 
I'm not trying to hurt your learning curve as we're all trying to learn how to fab and gaining knowledge from the guys above is crucial. I would probably leave welding cast to one of the pros around here like marsfab or someone else because your suspension is the most critical part of your vehicle for safety. You don't want a cracked housing or suspension failure going 70mph down the road. you know?! Good luck either way you go. Let us know what you decide and how it works for you.

About the truss: Why is the pure jeep truss your pick? Are there not any companies that offer a 1pc truss that goes around the housing and attaches to both axle tubes but not the housing like marsfab was asking? Just curious.
 
Jeff B said:
That 6011 wont work well on the cast housing. Clean it if your gonna stick it run a 7018 & skip around with the weld. ping it between welds.
Click to expand...

Yeah, I meant mostly on the tube where its hard to get to and has tons of paint and oil on it. Mostly, it was sarcastic. :)
 
Dana center sections are cast steel, not cast iron. Big difference weld it..
 
C's are cast steel also from what I'm told.
 
Jeff B said:
Dana center sections are cast steel, not cast iron. Big difference weld it..
Click to expand...

Cool. I didn't realize the housings were cast steel. I thought the C's were but didn't know about the center section. Good to know!
 
preheat to approx 900 degress. this is not that hot for welding. To do so take an oxy fuel torch and set it to a rich setting producing excess soot. Take the torch and soot the part and then adjust to a neutral flame. Preheat the area at a stand off of a few inches. This prevents the soot from being burnt by the flame. When the part reaches approximately 900 degress the soot will bake off giving you the desired preheat. ( this is a trick to get a kbnown preheat without a temple stick, accetylene soot burns at approximately 900) Also excellent for thicker aluminum plate.
Now this is the way I preheat alot of cast steel housings, radius arms, knuckle c's excetera. Yes you should be concerned with seals and such. I would have the diff torn down completely to do this and maybe on the bench, yes I am that anal when I work. If you don't want to go to this extent, preheat to cook off moisture in the metal (all metal is porous and holds moisture) warm to the touch. Set the welder up to weld (min) to weld 5/16 in a single pass (preferably hotter for the housing. Weld hot slow cool. Their is a shaved fourteen, and a couple extended Ford radius arms on this forum taking some good abuse welded with the procedure described, no worrries.
 
I skipped the axle truss and just welded the gussets. I also welded on some control arm skids at the same time. It went well. I just took my time so as not to overheat the ball joints. I did an inch or so at a time, then went to the other side and welded there, giving it a lot of time to cool in between. Thanks for the help guys.

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WARRIORWELDING said:
preheat to approx 900 degress. this is not that hot for welding. To do so take an oxy fuel torch and set it to a rich setting producing excess soot. Take the torch and soot the part and then adjust to a neutral flame. Preheat the area at a stand off of a few inches. This prevents the soot from being burnt by the flame. When the part reaches approximately 900 degress the soot will bake off giving you the desired preheat. ( this is a trick to get a kbnown preheat without a temple stick, accetylene soot burns at approximately 900) Also excellent for thicker aluminum plate.
Now this is the way I preheat alot of cast steel housings, radius arms, knuckle c's excetera. Yes you should be concerned with seals and such. I would have the diff torn down completely to do this and maybe on the bench, yes I am that anal when I work. If you don't want to go to this extent, preheat to cook off moisture in the metal (all metal is porous and holds moisture) warm to the touch. Set the welder up to weld (min) to weld 5/16 in a single pass (preferably hotter for the housing. Weld hot slow cool. Their is a shaved fourteen, and a couple extended Ford radius arms on this forum taking some good abuse welded with the procedure described, no worrries.
Click to expand...

I have a few sets of ford knuckles running around, simular process to yours. my oven at the house only goes to 500*:D
 
I found that a gas grill works great and keeps the house cooler too! I can't say I thought of it first, MUDPRO got me doing it after we started preheating some of the rockwell mohawks that way.
 
:D I'll remember that...
 
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