Welding Tips and Tricks

hey all,

I am currently working on a minitruck project and I need to weld some airbag mounts and 4-link pivots onto my toyota hilux (tacoma) diff housing, does anyone have any experience doing this?

I am a little bit worried about heat and the housing warping... aside from building a jig to bolt it down to before I weld does anyone have any suggestions?

I have heard mixed opinions on this, some guys I know who build these things all the time say they never have any trouble... some guys, say you must have it bolted to a jig, or get it re-aligned when your done!

I really want to get this right as diff's aint cheap, and I really dont want to be changing wheel bearings every couple hundred miles!

Are you simply welding brackets onto the axle tubes or will you be welding to the cast housing? Axle tubing is a no brainer as it is just mild steel, however you may want to build a fixture to be able to clamp it down and restrain it during and after welding to keep the tubing straight(depends on the amount and placement of heat and welding to be done).

The cast housing where the carrier resides is a whole nuther deal. Welding steel to the cast housing requires a bit of planning and some filler with fair amount of nickel to help with the underbead cracking. Preheat of around 350 to 400 before and during welding and a slow cool (think insulation blanket) back to ambient.

Last time I did spring mounts on axle tubes I built a jig. Like you said a lot of guys said it was unnecessary, however they weren't going to pay for a new diff if it warped.

If the brackets are to attach to the pumpkin, build them to bolt on. Use grade-8 hardware in the correct length, drill your parts precisely, and take advantage of bolt-shoulders to locate the parts precisely. You'll be much happier than trying to weld directly to the housing.

If you're welding to the tubes, as others have said, the risks are much lower. Particularly if you put effort into heat control.

Steve S

I remember rebuilding my old 12 bolt that came factory in my 70 RS/SS Camaro. I was cleaning the thing up and wondering where all of that grease came from. After I got it clean enough to look it over for leaks, I found that the factory plug welds where the axle tubes were pressed into the cast housing were welded at the factory were leaking. In fact the welds were so poorly done, appeared to be SMAW, they had burned through and actually had a hole all the way into the inside of the housing/axles. I cleaned it up as well as I could and then proceeded to cook out anything that would and cleaned it again. Whipped out my lil Hobart Handler and started on the outside of the plug welds and spiraled around until I had the entire plug filled in and ground it off flush with the housing. Welded a fillet weld around the tubes to the housing to further help keep the tubing from spinning inside the housing(should I happen to find enough traction). Painted it back up and rebuilt it with a new Eaton Posi with a new 3.73 ratio gear set, 4340 pinion yoke and sealed it up with a nice DTS diff cover with bearing preload bolts. Never has leaked.

Why not build a jig, that will become part of the final results?

IE: Truss your housing. Small tacks while you're getting everything in place, then once everything is done, burn it all in a couple inches at a time. Jump around to prevent issues with it walking on you, and when done your project is that much cooler (and stronger!).

I know that this is kind of an older thread. But, if I recall correctly, Toyota axle housings are stamped steel. The differential is cast. But you wont be welding anything to it. Ive built quite a few 4 link suspensions for Toyota 4x4s. Never had a problem with warpage. Just tack everything in plac. Then alternate sides when welding