XJ D44 rear truss

[waxer]

Well its been at least 4 years since I bent tube. I decided I would try out this Bend Tech EZ software and see how much tube I could waste in the process.

I did a quick and easy design on the program for a truss to add a little strength to my D44 rear. Bought a stick of 1.5" x .120 HREW and went to town.

Pinion needs to be at 15* Positive (to point at the tcase minus 2 degrees for torque deflection) and the spring perches need to be at 2* Negative (OEM perches were 6* Positive) so I had to cut the OEM ones off.

I'm sure others have done better and there probably is a better way to truss an axle, but this was my humble attempt at doing mine while not wasting a single inch of tube.

Hope these pics and experiences can spark an idea in someone to do something similar.

Any questions, feel free to ask.

 

[Kittrell]

That is possibly the cleanest XJ 44 I've ever seen. A thought, maybe bring the truss down and notch it so that it rests on the pumpkin. Then run a few beads there.

 

[waxer]

Hmmm, I'll take a look at that tomorrow before I get close to welding it up.

Looking at a few pics I can see that it appears that its not perfectly parallel with the axle (might have one notch off an 1/8" or so) no big deal, a little grinding will take care of that.

 

[gearwhine]

might have one notch off an 1/8" or so

you'll never notice once it's on.

and I agree with 91 jeep project, lower it a bit and give welding to the pumpkin a shot. If you're not comfortable welding to cast, look into buying a heavy duty diff cover and attaching that to the truss. Just try to connect them together somehow.

and my god, how did you cut and move that truss so well in the picture 91?...if it weren't where it attaches to the axle tube, it looks like it's really there.

 

[Kittrell]

Thats what I get for being lazy..........:repair:

 

[waxer]

The more and more I look at these pictures, the more I realize I should have made it a lower like you suggested.

I'm definitely going to bring it down close to the diff tomorrow. Check for square, and weld that puppy up.

Thanks for the ideas and opinions.

 

[TrailHunter]

Looks like it should do the job. I would bring it down but welding it to the pumpkin isn't really that important IMO if it's just a truss. It would be more important if you were hanging some links off of it.

 

[Kittrell]

Looks like it should do the job. I would bring it down but welding it to the pumpkin isn't really that important IMO if it's just a truss. It would be more important if you were hanging some links off of it.

Sure it'll be fine, but why not? It'll only take another 10-20 minutes of his time.

 

[CRASH]

Why do you have two bends in the tube? You've defeated the triangulation effect by having a bunch of unsupported tube between the bends.

You should have put a single bend in the tube above the diff, welded it to the diff, and then filled the voids between the tube, the diff, and the axle tubes with .120 plate. Then you'll have a real truss.

What you have there is not going to help keep that axle straight at all. Trust me, I've bent several rear axles.

 

[waxer]

Why do you have two bends in the tube? You've defeated the triangulation effect by having a bunch of unsupported tube between the bends.

You should have put a single bend in the tube above the diff, welded it to the diff, and then filled the voids between the tube, the diff, and the axle tubes with .120 plate. Then you'll have a real truss.

What you have there is not going to help keep that axle straight at all. Trust me, I've bent several rear axles.

At all? It'll help a little bit, but nothing compared to the design you are describing. The good news is I haven't welded anything yet. I've got plenty of tubing left, and more importantly I posted this first design on Naxja so as to get feedback such as this about the design.

Now with your /\ design, do you think there would be any strength lost if instead of putting in plate to completely fill the inside of the truss, but using tube to triangulate things?

Whats your opinion on that?

 

[CRASH]

At all? It'll help a little bit, but nothing compared to the design you are describing. The good news is I haven't welded anything yet. I've got plenty of tubing left, and more importantly I posted this first design on Naxja so as to get feedback such as this about the design.

Now with your /\ design, do you think there would be any strength lost if instead of putting in plate to completely fill the inside of the truss, but using tube to triangulate things?

Whats your opinion on that?

It depends on what you are trying to do, if you are trying to keep the axle straight under landings, extreme loads, than using additional tube gussets down to the axle tube will be good. If you are also trying to keep the tubes from spinning in the housing, you'd be better off putting in the single bend, then tying it into the diff cover or the diff itself.

Doing the plate is not hard, just use cardboard templates, transfer to sheet steel, and grind/torch/plasma the shape. The plate kills the above two birds with one stone.

 

[waxer]

No landings... I'm a rock crawler so I'd say excessive loads would be what I'm countering.

I know how to transfer the design with cardboard Been there, done that. Man I miss having my plasma tho.

I'm looking at countering vertical loads from the stresses of rock crawling. I'm not too worried about spinning the axle tubes. I'm a very light pedaled driver. I prefer to idle over obstacles as opposed to just spinning tires in a mad frenzy.

So I will look at changing the design to this -----> /\

I'll use tubed gussets inside the truss and post pics of the mock up.

Thanks for your input.

 

[waxer]

I've never welded to cast tho. I'm using a MIG with C25. Any tips on welding to the diff? Will it even be possible?

Thanks again.

 

[Jump This]

Well....some one answer this before I start welding!
Rick R:sunshine:

 

[BrettM]

pre-heat and post-heat with a propane torch or something similar. it really isn't that hard.

 

[FarmerMatt]

It's not the "proper" way to do it, but I just make sure the base metal isn't "cold", burn in the weld, & allow it to cool slowly. My welds haven't failed yet... YMMV

Matt

 

[BIGWOODY]

I've never welded to cast tho. I'm using a MIG with C25. Any tips on welding to the diff? Will it even be possible?

Thanks again.

we use nickle rod and pre-heat....hasn't cracked yet

 

[tealcherokee]

youll have no problems using your mig, heat it up, and use some heat to cool it slooooowwww

 

[Mr.OverKill]

here is my proto type truss for mine, thinking bout the link set up now as you can see

i need a better digi cam but you get the idea. 2x4 1/4 wall tubing

 

[BrettM]

here is my proto type truss for mine, thinking bout the link set up now as you can see

i need a better digi cam but you get the idea. 2x4 1/4 wall tubing

that looks real good, but you might want to continue the steel all the way over the diff to give you a nice place to weld link tabs to.

also, you should make a stencil off that tubing before you weld it on, you could probably even sell the stencil for a few bucks as it would sure save a lot of fitment time for people wanting to do the same.