Just so I have a starting point for my own long arm setup, can someone please tell me what thread size RE uses on their TJ long arms.

The thread size I am referrig to is that of the studs that are welded to the shells of their spherical bearings that then thread into the bungs of the long lowers/uppers.

I'm assuming that a 3/4-16 shank should be sufficient, but I'm curious to know what RE does.

I'd call them myself and ask, but I don't feel like being put on hold half a dozen times just to ask a simple question.

cmk

I don'n know about RE, but my friend used 1-8 unc threaded rod for his arms because tubing with a 1" ID is the correct size to be tapped (I think it cost him $10/arm at a local machine shop). The tubing size he used was 1-3/4 x .375 wall dom and has worked well.

I used 1 - 8 unc threaded rod from the local harware store like $8 for a 36" lenght

2 large nuts an 1 nylock nut. RE uses UNF thread 1" rod.

Here is a pic
http://home.off-road.com/~dkf/combat-eng/J-arms.JPG

You should call them. They answer questions all day. most of them are what size tire will fit what lift..:flipoff2:

harsanyj and kodak,

Thanks a ton guys! That is the exact info I needed. harsanyj even answered another question I had which was "what size DOM is ideal for a long arm setup."

kodak's J arms look excellent and I'll probably be copying most of the ideas he implemented.

cmk

I'm not for sure, but I think that my RE kit uses alot bigger thread then one inch. I've seen all of the long arm kits on the market, and the RE kit is the best for size of tube.:eek:

I scoped out a length of 1-8UNC at the hardware store yesterday and no, it doesn't appear to be nearly as big as what RE uses. But, it does appear to be heavy enough.

Preliminary plans look something like this:

http://pages.prodigy.net/coolmank/pics/misc/long-arms.jpg

For the main body of the arm, the 1-3/4 x .375 wall DOM that harsanyj recommended does work very well with the 1-8UNC threaded rod.

I was hopng to build the arms turnbuckle style with right hand threaded hardware at one end and left hand threaded hardware at the other. But LH hardware runs 2 to 5 times as much as RH.

e.g. From Fastenal:

A box of 25 RH 1-8UNC Jam Nuts runs $16.39

A Box of 25 LH 1-8UNC Jam Nuts runs $78.27

I think for the sake of having a modular system where I can swap pieces all around (and for cost's sake), I'll just stick with standard RH stuff.

cmk

CMK-
I just remembered that it was a 1-1/8 - 8 UN thread (not 1-8 unc) that he used. This size allows 1" id tubing to be tapped with no boring. Sorry for any confusion.

RH only should be fine. once you set the lenght it won't change. turn buckles make it easier to adjust. but is it worth the added fabrication price?

Originally posted by harsanyj
CMK-
I just remembered that it was a 1-1/8 - 8 UN thread (not 1-8 unc) that he used. This size allows 1" id tubing to be tapped with no boring. Sorry for any confusion.

No problem man. I think in the end though, I'm going to stick with the 1-8UNC. It would be cool to tap the DOM as well, but without access to a lathe, I would have to farm that out ($$$). The cost of the tap alone would probably put me "over budget."

Originally posted by kodak
RH only should be fine. once you set the lenght it won't change. turn buckles make it easier to adjust. but is it worth the added fabrication price?

$78 versus $16 ... heeeel no

cmk

You can get the jam nuts cheaper than that I'm sure....

Having one side LH and the other side RH is a HUGE advantage...I wouldn't do it other way.

I use 1.5" OD with .250 wall, which gives a 1" ID.

CJ

I think they are 1 1/4 -12

Why do you say that CJ? I understand that you can adjust them more presicely but I have been leaning towards the ease, cost and reliability of a single joint.

It is really really nice to be able to loosen the jam nuts and just twist the bar to change the length. Have you looked into finding some bushings that have essentially threads on them and a bushing? It may be hard to find some to fit in the factory brackets...I know I've seen rubber bushings with 3/4-16 threads and 3/4" bolt hole.

CJ

Originally posted by CJ Lagos
It is really really nice to be able to loosen the jam nuts and just twist the bar to change the length. Have you looked into finding some bushings that have essentially threads on them and a bushing? It may be hard to find some to fit in the factory brackets...I know I've seen rubber bushings with 3/4-16 threads and 3/4" bolt hole.

CJ

Speaking of bushings, do you know of any good sources for them?

That one detail has me stuck and I don't feel like buying the bushings from RE as well as the spherical bearings.

cmk

Yes, find some people with stock control arms and take them off their hands. I have a whole bunch of Rubicon Express adjustable arms that I'm going to put new bushings(from my stock arms) in and rebuild the joints on and sell...just gotta find the time.

CJ

IMO the RE joints are the best of that type because of their ability to be preloaded.

The problem with stock bushings is that they have a "steped" design which means the inside of the end of the arm has to have a step machined into it.

Dug is dead nuts right on. This past weekend, a buddy of mine used stock bushings for his arms and they had to have a dude custom mill the shells in which to press the bushings into because of that step. It's kinda' nice when there's a CNC mill available and a dude that has nothing better to do than program it to crank out 8 custom shells.

I'm hoping RE's bushings don't have that step. Now I just need to find out what they use.

cmk

Originally posted by cmk

I'm hoping RE's bushings don't have that step. Now I just need to find out what they use.

RE uses stock bushings they buy from DC.

Paul

You don't need to machine the step... just a big press. (RE doesn't have a step in there arms)

Oh, in that case, will 100 tons do? :bloodyhand:

Welby also brought up some good info in this thread.

http://www.pirate4x4.com/forum/showthread.php?s=&postid=301549#post301549

cmk

Originally posted by harsanyj
You don't need to machine the step... just a big press. (RE doesn't have a step in there arms)

That makes it fun if you have to change a bushing on the trail or on the road somewhere......

Originally posted by DUG


That makes it fun if you have to change a bushing on the trail or on the road somewhere......

What are the odds of that? Even if the bushing spontaneously combusted, you'd be OK to drive it home, just a little sloppy :D

Originally posted by Welby


What are the odds of that? Even if the bushing spontaneously combusted, you'd be OK to drive it home, just a little sloppy :D

If I'm out of state on a week long trip and I fry out a bushing bad I don't want to have to limp on it for the rest of my trip.

This is just me. I have a thing where I like to know I can fix just about anything on my rig where it sits.

Even if you machine a step in the tubing, it is still a press fit, right??

Originally posted by DUG


If I'm out of state on a week long trip and I fry out a bushing bad I don't want to have to limp on it for the rest of my trip.

This is just me. I have a thing where I like to know I can fix just about anything on my rig where it sits.

Hear what your saying, but it's just not that critical of an item, that it couldn't wait. Would get annoying on a long trek home though. Besides, those things are pressed in. No way you'd be able to get a new one in there by hand.

cmk, why not use spherical joints at both ends of the arms? With only one joint in the RE arms they still bind and is a lot of the problem of the axle brackets tearing off and the bushings wearing.

I have RE adjustable lower control arms. The barrell on the bushing end on mine was all tapped and grooved for a sperical joint already. I cut the bushings out and jointed both ends. No bind at all now, no bushings to replace every two months. :D

There was not an increase in vibration at all either. I am too starting on a long arm kit, joints at both ends it will be.

Originally posted by TJoop
cmk, why not use spherical joints at both ends of the arms? With only one joint in the RE arms they still bind and is a lot of the problem of the axle brackets tearing off and the bushings wearing.

I have RE adjustable lower control arms. The barrell on the bushing end on mine was all tapped and grooved for a sperical joint already. I cut the bushings out and jointed both ends. No bind at all now, no bushings to replace every two months. :D

There was not an increase in vibration at all either. I am too starting on a long arm kit, joints at both ends it will be.

Now that mention it, I might do that with mine.. The front rubber bushings are fine, and I get tons of flex. I have my swaybar off in the back, and I think all the twist on droop is what's chewing up my bushings in the rear...Is it just a matter of throwing the spherical joint in there, similar to if I was replacing the axle end spherical joint? And what do the joint kits cost?
Thanks, Mark

FYI...
One thing to consider when doing a long arm and using all spherical joints is that unless you build a 4link with equal length and parallel bars, you will get serious binding. With a stock suspension the links are pretty close to parallel and equal length so that is not an issue.

Originally posted by Welby


Is it just a matter of throwing the spherical joint in there, similar to if I was replacing the axle end spherical joint? And what do the joint kits cost?
Thanks, Mark

Exactly. Double check, of course, if your arms use the same barrell at both ends. At the bushing end you should be able to see the tapped hole for the set screw. Be careful cutting the bushing out so you don't bungle the threads for that preload disc washer thing. :D

I took the the spherical joint out of a set non-adjustable arms I had sitting here so I am not sure on price of the components.



EDIT: I only did this to the lower arms mainly so I didn't have to keep replacing the bushings. I have not had a problem with the uppers.

Originally posted by harsanyj
FYI...
One thing to consider when doing a long arm and using all spherical joints is that unless you build a 4link with equal length and parallel bars, you will get serious binding. With a stock suspension the links are pretty close to parallel and equal length so that is not an issue.

Joe,
So you are saying the bushing acts as a cushion during suspension cycling whereas the joints would transmit to the mounts?

TJoop,

I'm gonna' stick to the standard spherical bearing/bushing setup for each arm for a couple reasons.

1) RE's spherical bearings are EXPENSIVE, about $50 each. Bushings are a bit cheaper as I'm sure you know.

2) I have to believe that the bushings will absorb some of the vibration, at least better than the spherical bearings do. It's not that I'm doubting what you said about the dual spherical bearing setup not adding any vibration, but maybe your butt has more vibration absorbing padding than mine. I'm a scrawny shiat.

The way I'm planning on building my arms, I can easily add spherical bearings at each end at a later date if I so choose and if the pocket book allows.

Once I have evrything set and tweaked, I'll probably rebuild the arms using the best joints at the best locations and with fewer mechanical connections. I purposely want to keep everything modular and adjustable until I get it all fingered out.

cmk

Originally posted by TJoop


Joe,
So you are saying the bushing acts as a cushion during suspension cycling whereas the joints would transmit to the mounts?

Look at an RE Long Arm or Tera Long Arm front suspension on the ramp (or XCL). You will notice on the uca bushing one side will be pushed all the way to the back of its cylinder. The other side will be pushed all the way forward. This is because the links want to rotate the axle in opposite directions. If there were all heims (or JJs) either the bracket would have to give or there would be no articulation. Now don't ask me how Skyjacker's LA kits work because in theroy they shouldn't. I think their UCA extension brackets must deflect or something.

You can get joints for about 40 bucks from Currie and I belive Roggy Ent. is selling them for about that.

The initial buy in is more but when you wear them out the overhaul is cheaper and easier then a new bushing.

IMO

I'm gonna' stick with RE's spherical bearings ($50 ea. through my buddy at offroadtoystore.com) because they've got adjustable preload unlike the Currie ones. Remember the ones I built over at your pad with that threaded ring that was a beatch to thread in because the heat from welding the studs on had distorted the shell?

Yeah, that was a beatch.

cmk