Long Arm Build for a TJ

[Tommy R]

Everyone, I get tons of e-mails and PMs from people asking me for information about this build. PLEASE be sure to read through the entire thread very carefully to see if your questions have already been answered! I spent a lot of time documenting this, partially for everyone's benefit here on JF.com. Please show me the same courtesy and before you e-mail me a question, please read this thread and my build thread (linked in my sig) to see if I've already answered it. If not, then feel free to just post up the question in either thread and I'll do my best to answer it there. Thank you very much!



Hey y'all,

Like many of us, I want a long arm suspension, but am not made of money. I am, however, fortunate enough to have a decent arsenal of tools and a buddy who was able to supply me with some steel for free-fifty-free! So I ventured out to fabricate a suspension. Since the steel I received was square tubing and not round DOM, I decided my best course of action would be to follow along the lines of what Clayton does for the most part. For those of you who've seen what geauxturbo fabbed, well, mine will be very similar.

I'm a capable welder, but it's far from my profession so if anyone with a keener eye than myself notices anything odd about my welds, please bring it to my attention. Building suspension components is way too important, IMO, to have a chip on your shoulder and not accept constructive criticism so don't hold back. FWIW, thus far I've used my 135 amp Lincoln welder, but I've got a borrowed 185 amp Hobart now at my disposal, too. I plan on using the bigger welder for the heavy stuff.

Here's a link to all the pics:
http://tommyr.smugmug.com/gallery/4505417_5Wpwa#265298122

Here's some pics of what I'm starting with. The raw steel:


Bushing sleeves and square tube threaded inserts:


A few of the Johnny Joints I'll be using:


Rough outline of the front radius arms. The upper piece of steel will be cut to make the upper control arms:


The chassis end:


The axle end:

[Tommy R]

First bushing sleeve welded into place:


Insert welded into place. Notice the holes in the arms for plug welds:


Plug welds filled and somewhat ground down:


A finished lower minus the bracketry to mount the upper to it:


Today I'll build the chassis mounts and upper control arm mounts. I'll post up pics either later today or this evening...

Tommy

[Matt Gertsch]

Square tubing isn't the best choice for control arms. The rectangular shape isn't as resistant to the forces found in control arms as the circular shape is. Take a look at all of the lift manufacturers on the market to see how many make square control arms.

Other than that, it looks like you're off to a good start and undertaking a project that few other jeepers are willing to undertake.

[Tommy R]

You're absolutely right, Matt, and given the choice I would've preferred round DOM, but that wasn't in the budget. I likely would've done nothing except that Clayton has been building and selling their square tube systems and I don't know of anyone who's been disappointed with them or broken them. So I thought I would give it a try. But yes, given similar thicknesses, the round tubing would've been stronger. That's why the square tubing has such thick walls to make up for it. It just weighs a lot more.

Tommy

[Scotch740]

Originally Posted by Matt Gertsch

Square tubing isn't the best choice for control arms. The rectangular shape isn't as resistant to the forces found in control arms as the circular shape is. Take a look at all of the lift manufacturers on the market to see how many make square control arms.

Other than that, it looks like you're off to a good start and undertaking a project that few other jeepers are willing to undertake.

Depends on what forces you are referring to. An impact on the corner, no its not as strong. An impact on the flat it is stronger. Square tubing (same diameter and wall thickness) is stronger in a bending, compression, and tension application. Discussed here Post 66 shows the calculations, or at least it use to, I can't see the pictures at work but I hope its still there. Theres a lot of people over there spouting BS like its CO2 but they have no facts or numbers to back it up.

Clayton makes their links with square tubing, and have you seen anyone with a better warranty for control arms?

CLAYTON Off Road Hard-Arm™ Suspension comes with the abuse-proof Limited Lifetime Warranty against bending or breaking of our control arms only.

I asked in your build journal but thought I would ask here again, where did you get those bushing and what are your plans for frame brackets. Also are you doing a triangulated 4 link?

[1 ton yj]

Yep, square is stronger in bending than round DOM of equal wall thickness is. That being said, I have 2"x.25 square lowers on my front 3 link and 1 3/4x.375" lowers on my rear 4 link. I bent one square link last summer, a very hard hit from landing the complete vehicle weight on it. A few minutes with a press and a torch and it was good as new. Both of my .375 wall round lowers bent within the first couple of trips just dragging them on rocks.

Another thing, although it's too late now, is always thread the joints completely into the insert before welding and do not remove them until everything is cool enough to hold onto without getting burned. Otherwise you will distort the threads, ruin the insert and sieze the shank of the joint.

One more thing I've learned through breaking stuff, is to have no more than 3-5 threads exposed on the joints in the lower links. Even with 1.25" shank they will still bend if you have a lot of thread exposed. Thread them in all the way, back them out 3-5 turns then measure your link.

I run the same joints, they are a great value, work well and are very durable.

Good luck!

Edit: you can see the slight bend in my lower link towards the frame end that that I straightened.

[Tommy R]

Thanks for the input, y'all. Good point about welding the inserts with the joints threaded in, but I was concerned with burning the poly bushings inside. Fortunately, they held up well with no distortion.

Finally got back from running errands (picked up the plasma cutter) so now the spark making can commence.

Tommy

[Scotch740]

Originally Posted by Tommy R

Thanks for the input, y'all. Good point about welding the inserts with the joints threaded in, but I was concerned with burning the poly bushings inside. Fortunately, they held up well with no distortion.

Finally got back from running errands (picked up the plasma cutter) so now the spark making can commence.

Tommy

I want a plasma so bad

Guess you missed it above but what are your plans for frame brackets, and are you running a triangulated rear? Also are you stretching your wheel base at all?

Nice build, I can't wail till I am in the position to do a long arm build. I plan to do the same as you, making your own, and add a little stretch to my front and maybe an inch or two in the rear for larger wheel well openings.

Keep us updated, and thanks for posting your build.

[Tommy R]

Oh, sorry... Yeah, I'll stretch is a bit. Maybe an inch up front and as much as the fuel tank will let me in the rear. I'll be fabbing some brackets to the chassis.....hopefully today, but I've got to make even more trips to the store now for.....stuff. :\

Tommy

[Dogman]

Nice! Where did you get those tube inserts? What kind of bushings are those and where did you get them?

[Bigbob]

Originally Posted by Dogman

Nice! Where did you get those tube inserts? What kind of bushings are those and where did you get them?

Ditto X2 here. I have never seen inserts like that. If they come in a 1.25" size they could be useful in making a tire carrier as well.

I sure have no issues with square tubing. I wager it is slightly stronger than the stock units. And for a do-it-yourself job the welds will be longer and less likely to fail. A 2" square tube will have 8" of weld around there. A 2" round will have about 6 1/4" of weld. Not that it really matters, just a thought. Bob

[Matt Gertsch]

Originally Posted by scotch740

Depends on what forces you are referring to. An impact on the corner, no its not as strong. An impact on the flat it is stronger. Square tubing (same diameter and wall thickness) is stronger in a bending, compression, and tension application. Discussed here Post 66 shows the calculations, or at least it use to, I can't see the pictures at work but I hope its still there. Theres a lot of people over there spouting BS like its CO2 but they have no facts or numbers to back it up.

Clayton makes their links with square tubing, and have you seen anyone with a better warranty for control arms?


I asked in your build journal but thought I would ask here again, where did you get those bushing and what are your plans for frame brackets. Also are you doing a triangulated 4 link?

However, it's much weaker against torsional forces, which are what controls arms most frequently encounter.

I have no idea what Claton's warranty is, but my round Rock Krawler arms come with a no questions asked lifetime warranty.

[Tommy R]

Only got a sec, but here's the link to the inserts. They only come in 1.5", though. But they're also available in LH thread.

http://www.4wdfactory.biz/osc2.2/product_info.php?cPath=78_79&products_id=242

Tommy

[jeepncreepn]

very nice im getting ready to do the same i got my joints from ballistic fab they have *****en joints and cheap also the the bushing is all DOM unlike alot out thier how long are your arms going to be including stretch if any also if u can ditch the springs and run air shocks way nicer ride and clean look

[1 ton yj]

Originally Posted by Matt Gertsch

However, it's much weaker against torsional forces, which are what controls arms most frequently encounter.

How does a control arm encounter torsional forces are you running bushings at both ends? I don't know about you but my control arms can rotate freely on the joints and are slammed and dragged against boulders almost constantly. Bending forces are the most likely encounter (unless you only wheel at the mall )

That's pretty cool that they make square tube insers now. I used round tube inserts in my square, it worked very well but the square inserts just look nicer.