Long Arm Build for a TJ - Page 13

blacklabel000 · 06-26-2009, 01:17 AM

ive got a question for ya tommy, that i havent seen answered (or asked) yet.

first off, this thread inspired me to build my own radius arms for the front of my xj, which i have been running for a while now. but i recently bought a new xj and am wanting to build another set of long arms for it.

anyway my question is, i saw that you did radius style on the front, but why did you do a 4-link in the rear? i dont know much about wranglers, but isnt the front pretty much the same as the rear?(track bar, 4 link from factory, etc.) and if you had to do it again, would u do a 4 link up front also?

im just wondering because ive done a radius already, and went out and bought 4 heim joints so i could try a 4link. but everyone tells me it takes alot of homework and is hard to do....

any input you have would be great!
thanks a ton for everything!-nick

DirtNMyTeeth · 06-26-2009, 01:32 AM

This is a great thread. Thank you for all the good info.

**Tommy R** · 06-26-2009, 01:35 PM

Blacklabel, that's a good question and, no, I don't think it's been asked. Thanks for checking!

Basically, unless you go with a full hydrulic steering setup, you want to keep a panhard/track bar up front so that you can reduce or eliminate bumpsteer.

For me, this means I'll be running a tried and true radius arm setup (like I am now) or it means I'll run a three link (which I'll do if I replace my front axle). If I run a three link, I'd run one upper link above the drive shaft and keep my current lowers. The upper would need to be offset to the side to avoid oil pan clearance issues. This is also a reason to be wary of a semi-triangulated front setup unless you plan on getting the Jeep awfully high up there....and I'm trying to keep mine relatively low.

And Dirt, thanks for the kind words.

blacklabel000 · 06-26-2009, 01:45 PM

oh alright i gotcha now, so to do a 4 link in the rear is no big deal.because theres no steering back there(obviously) but when you get into that up from your going to have to look into upgraded steering and what not. ok great its all making sence now. so to do a 3 link(in your situation) all you would do is take both uppers out completly, and build another longer upper that went to the frame or a crossmember.

one more question while i gotcha here, why would you run a 3 link ONLY if you went to another axle? do you plan on trussing before you 3link? is that something i should look into? or should i just run it off the stock bracket above the pumpkin?

thanks for all your time tommy, i really appreciate it.
-nick

**Tommy R** · 06-26-2009, 02:20 PM

I suspect the cast upper in the D30 pumpkin would be fine, but long term I would prefer to replace it with a Johnny Joint or something to get that rubber bushing out of there. The main reason I wouldn't worry about a 3 link with the D30 is because it's a bit of fab work that I may prefer to do only when I'm going through the hassle of putting in a "real" front axle. The current setup works pretty darn well right now so it's tempting to just leave it as is, y'know?

Happy to help, Nick. Let me know if you have any other questions!

Tommy

**Tommy R** · 08-17-2009, 04:00 PM

Josh asked me a question via PM that I don't believe has been answered here so I'll address it now.

Quote:

i've not been able to find is (1) how you determined the placement of your control arm brackets (front and rear) and (2) how you determined where to mount the upper control arms on the lower control arms themselves (i'm refering to the front radius arm setup).

1) I basically used the stock skidplate as a guide for the front mounts. I left 1/4" between the front chassis mounts and the front of the skidplate. 1/4" plate worked perfectly as a spacer.

I wanted the front and rear lower arms to be pretty similar in length, but that ended up not being the case. I made the front arms, decided they were shorter than I'd like, so I used them in the rear and made slightly longer ones for the front. Eventually I'll make longer rears when I stretch it.

2) It really doesn't matter much where you put this, IMO. Just ensure that you won't have clearance issues as the suspension cycles.

Keep in mind when I built mine I used visual inspection of other long arm kits as well as Lance's (geauxturbo) custom long arm build for guidance. Lance lives in my hometown and he was kind enough to let me take some measurements. They weren't all used, but at least helped me determine an approximate starting point.

Tommy

ET48 · 08-31-2009, 01:34 PM

Quote:

Originally Posted by Tommy R

It rides great! Tracks straight, too!

Tommy

So you think it rides better than the short arms?

There is no worry about only having one front axle radius arm? The second was just providing more of a hassle than needed?

No problems with excessive axle movement while driving down the road?

Is there any advantage to have your johhny joints near the frame instead of at the axle mount or vice versa?

Thanks and great job!

**Tommy R** · 08-31-2009, 04:00 PM

It definitely rides better than with the short arms. No comparison. But I'm running both radius arms up front now for two reasons. 1) I didn't see any improvement in offroad performance with just one and 2) I felt more comfortable with two uppers in place in case any bolts accidentally backed out or sheared. But otherwise, the single radius arm setup worked fine. If/when I re-do the front axle I'll build a single upper link and sell these radius arms.

Ideally, I'd run JJ's at the axle and chassis ends, but it's too much money and I don't know if it's necessary. It flexes more than my shocks can handle as it is.

Tommy

**Apex** · 09-01-2009, 09:11 PM

Awesome build, just read it for the first time. Lots of good information and ideas in here.

A few questions though.

If I recall correctly, your front LCA brackets are angled a bit, how did you figure out what angle to set it at?
Your rear truss, what specs did you use when building this sucker up? Height, width, UCA bracketry, etc.
Did the truss interfere with your stock brake line's location? I saw that you said you had to relocate the diff vent tube, that is why I am asking...

Brian

**Tommy R** · 09-01-2009, 10:43 PM

Quote:

Originally Posted by Jeep02Apex

Awesome build, just read it for the first time. Lots of good information and ideas in here.

A few questions though.

If I recall correctly, your front LCA brackets are angled a bit, how did you figure out what angle to set it at?

I just angled them so that the brackets would line up solidly under the frame rails.

Quote:

Your rear truss, what specs did you use when building this sucker up? Height, width, UCA bracketry, etc.

I just kept it as low as possible to prevent hitting the tub under compression since I knew I would have plenty of separation. Basically, I looked at all kind of other long arm kits and emulated what they did. BUT, that's also why I built some adjustment into it, too, so I could tweak it to suit me. So far, I've had no need to change it at all.

Quote:

Did the truss interfere with your stock brake line's location? I saw that you said you had to relocate the diff vent tube, that is why I am asking...

Brian

I had to relocate the vent tube, yes. I also had to relocate the "T" fittings and some brake lines, but there was nothing to that. Easy peasy.

Tommy

**Apex** · 09-01-2009, 10:51 PM

Thank you for taking the time to answer some questions. Your build is pretty inspiring. A wheeling buddy and myself may be doing something very similar shortly.

Thanks again!
Brian

**Tommy R** · 09-01-2009, 10:55 PM

No problemo! Let me know if I can be of any more assistance with pics, info, whatever.

Tommy

**Apex** · 09-01-2009, 11:02 PM

Well in that case, I will be in touch lol.

dcorn · 09-02-2009, 12:16 PM

Quote:

Originally Posted by Tommy R

Ideally, I'd run JJ's at the axle and chassis ends, but it's too much money and I don't know if it's necessary. It flexes more than my shocks can handle as it is.

Tommy

Read up on Pirate 4x4, it is NOT recommended to run solid joints on both ends of a radius arm setup. Based on the design, they create bind which is soaked up by the soft bushings on the axle side of the uppers.

**Tommy R** · 09-02-2009, 12:24 PM

Yeah, I should've clarified. With a radius arm setup, you need to run rubber bushings somewhere in the axle mounts or it can bind pretty badly. Having rubber uppers should be sufficient, but having rubber lowers also doesn't hurt, either.

If you run a single radius arm, then no rubber needs to be used. In my post above, I was referring to running JJ's at both ends of the lower arms, but not the uppers.

dcorn, thanks for bringing up that point!