Alright, here is my idea for some booty fabbed suspension links. The goal is a cheap link that will hold up to moderate abuse for a 4-linked double triangulated rear end on an EB.

The plan is to use 2" .25" DOM. I also want to use poly bushings at each end of the link (for ride comfort and price), but I don't think that they will give me enough flex with a standard link. Not to mention they aren't adjustable.

So my idea is to put a joint in the tube close to the frame end (as close as possible) that spins on itself. What I want to do is buy a threaded tube adapter from the notorious P-I-G on one end. That gives me a spot for a 1.25" grade 8 bolt. Take that 1.25" grade 8 bolt, round the head, plug weld it and weld the bottom completely for the other side of the link.

This should allow the links to spin on the threads and have some adjustment. So what do you guys think? Will I die on the trail? Will it bend when I take it out of my driveway?

-Jack

It seems like a good enough idea, but one thing would concern me. If the fit between the nut and bolt wasn't 100% perfect, I would be worried that the joint would bind and cause something to bend or snap at the more extreme limits of flex.

That's not a new idea. I've seen it before. I just think it'd bend if you really beat the link on a rock.

After some thinking, I adjusted my post to using threaded tube adapters rather than bolts... You don't think that a 1.25" grade 8 bolt will hold up well?

Also, as to the binding, I'd make sure I was a couple of turns out on the adjustment to keep from binding.

Thanks for the comments so far.

-Jack

Definately booty fab. Poly bushings on the frame end on the lower links won't have enough sideways misalignment capabiltity.
And 3/4 hardware (even grade 8) doesn't sound strong enough to take rock punishment unless they were very well protected by the frame. Not to mention the fatigue from rattling, which it will do. That's not near enough contact area between the threads to keep from loosening very quickly.
If I understand this right, you plan on welding the bolt head to the body of the poly bushing? If so, it's going to be very difficult to keep the weld junction from going to hell in a hurry because of the small weld area and sideways forces. I hate relying on the quality of one weld to keep stuff from scattering on the trail/ highway.

Originally posted by ROCKSFORBRAINS
Definately booty fab. Poly bushings on the frame end on the lower links won't have enough sideways misalignment capabiltity.
And 3/4 hardware (even grade 8) doesn't sound strong enough to take rock punishment unless they were very well protected by the frame. Not to mention the fatigue from rattling, which it will do. That's not near enough contact area between the threads to keep from loosening very quickly.
If I understand this right, you plan on welding the bolt head to the body of the poly bushing? If so, it's going to be very difficult to keep the weld junction from going to hell in a hurry because of the small weld area and sideways forces. I hate relying on the quality of one weld to keep stuff from scattering on the trail/ highway.

From what I read, he is wanting to basically build a regular link, then cut it in half and make a twisting flex joint in the middle of it by inserting a bolt in one half and a nut in the other, then screwing them back together.:question:

The bolt will be a 1.25" bolt and it will be welded to the inside of tubing not butt welded to the bushing frame. That way it is both plug welded around the tube (probaly in 4 spots) and then on the end of the tube around the head.

I agree, I don't like having a place where there is no redundancy, but I don't see how I can get away from it.

BTW, the joint will be link 1" down from the poly bushing on the frame end. I'm hoping that the bending forces will be less there and impacts there won't be often.

-Jack

Just saw your edit. 1 1/4 sounds better, but I still worry about those poly bushings not having enough sideways flex and still not enough contact area on the threads to keep from self destructing.
Are you planning on making them "wishbones" or just keeping all the links separate?

Josh, that's right but the joint will be at the top of the link not in the middle.

Rocks for brains, they will be independant links that are all triangulated. So there should only be forward and back forces not side to side. SHOULD BE...

-Jack

BTW, I was thinking of using leaf spring bushings (1.5 OD x 2.5" wide with a 9/16" sleaved hole.

I was thinkinga bout doing this to save money too, but changed my mind. I cant see anything wrong with it. It would help a lot as far as flexability goes. Plus you wouldn't have to buy heims or JJ's.

Only thing is you still MIGHT lose a little flex from the poly joints, but not much. Cause when your suspension is articulating, the link doesn't just need to be able to twist, it need to move side to side as well. Ya see what I'm saying. But the loss would be minimal compared to the money saved. I'd go for it and laugh at all the people that spent big money on their suspension joints.

:D

I think your proposed setup would probably survive fine on the upper links; however,
Depending on where your roll axis ends up, the lower links will probably see substantial sideways motion and will put a bind on the poly bushings as the axle articulates at an axis somewhere above the top of the pupkin if the upper links meet at the axle .
Compare the cost of those burly 1 1/4 tube inserts and grade 8 hardware and poly bushing to a high quality 3/4 or 1" heim and the necessary tube insert. I've seen chromolly heims w/ teflon/kevlar and 28,000 psi go for $24.

Originally posted by jesselt
I was thinkinga bout doing this to save money too, but changed my mind. I cant see anything wrong with it. It would help a lot as far as flexability goes. Plus you wouldn't have to buy heims or JJ's.

Only thing is you still MIGHT lose a little flex from the poly joints, but not much. Cause when your suspension is articulating, the link doesn't just need to be able to twist, it need to move side to side as well. Ya see what I'm saying. But the loss would be minimal compared to the money saved. I'd go for it and laugh at all the people that spent big money on their suspension joints.

:D

The problem I see isn't loosing flex so much as putting undue stress on the body of the bushing. If your going to try it I would *strongly* recommend, after welding the bushing to the link, wrapping a 1/8 or 3/16 flat bar gusset around the bushing and extending an inch or so down the side of the tubing of the link then weld up.

why not buy the poly bushing/threaded link ends from avalanche?

the plan is to put a pre-load into the links so there is very little side to side movement required. The links, when viewed from above, will look like XX. The lowers will go from outside the axle tubes to converge below the output shaft and the uppers will go from the pumpkin to the frame.

I like the idea of the sleave around the bolt extending out and I'll probably go with that.

As for cost, here's what I'm estimating...

$40 for the bushings from 4WPW (with tax)
$FREE$ Tubing I have plenty of
$20 x 4 for tube adapters (with tax and delivery)
--------------------------------------------------------------
$120

for heims (low estimate)

$24 x 8 (with tax and delivery)
$20 x 8 tube adapters
--------------------------------------------------------------
$352 (that's not even counting high mis-alignment bushings, etc.)

The Avalanche units are sweet but they are $34.95 each.

I'm unemployed so I need to keep costs down. If I don't like the links I can always rebuild them with heims when I have a job but I don't want to die in the process.

Please keep the info coming. Do you think 2" tube underneath is too heavy? Perhaps 2" tube on the bottom links and 1.5" tube (with a smaller bolt) on the uppers?

-Jack

RFB, I just re-read what you wrote. I'm not welding the head of the bolt to the tube that the bushing will go into. I'm putting a fish-mount into a piece of tube to make a T and the bolt will be ground down to the ID of the fish-mouthed T and welded up nice and solid.

IRONBENDER............ don't be a HACK. Click http://www.polyperformance.com/allthread.htm

We just got this chit in. The next batch of tube adapters should be done in another week. match that up with some RE joints ($33.99) and be DONE. There is no reason to be a HACK....

I think that the only way to make an link that twists that won't wear out and be weak is to use Acme threaded rod. At least I think thats what its called. It has threads that are designed for linear movement as opposed to clamping. Regular threads have the wrong pitch to deal with this kind of force without quickly wearing out. I tested this on and my links were trashcanned quickly and replaced with category II toplinks found at the local farm equipment dealer or farm store. They are biult to hold the top part of a 3 point hitch on a tractor and I "think" are rated at 40,000 pounds. $30 got me 4 links that have 1 1/8" holes have a pretty good misalignment and for me have not yet broken or worn out in over 2 years and 20,000 miles of driving and wheeling. Anyway just a thought to consider since they are the same price as your budget and I think they would last longer.

Tera (http://www.teraflx.com/) has been using threaded links for a long time.

Did that on all four lower links on mine, using the old CJ Main eye bushings from my leafs. Going on 5 years on the original spring bushings reused in the front, and 1 year on the new ones installed in the rear. No issues at all and as usual, cheap cheap cheap. :D :D

I also used 1.25" grade 8 bolts and the matching nuts on the control arms. I did manage to slightly bend one bolt when I slammed into a rock ledge trying to get the control arm to skip me up onto the ledge, but my 42 just went under the outcropping and nailed the control arm. No failure, just tweaked the bolt.

Ed

Piggy, RE joints break the bank $35 ea plus tube adapters. But I dig the new allthread. Perhaps rather than use a bolt, use that althread instead... I can run it up further in the tube and get more spot welds in for a better hold. What grade is it and how long of a piece do you get for your $15.

I don't want to hack things up either. But I want to hit the trail and if I stick to conventional it will be quite a while until I get there.

RockTaxi, very good info, thanks!

Blair, I heard that the tractor joints were super loud and got sloppy quick. What is your opinion?

BG. I checked out the TF links and they are similar to what I'm thinking...

http://www.pirate4x4.com/forum/showthread.php?s=&threadid=104732&highlight=b7+threaded+rod

http://www.pirate4x4.com/forum/showthread.php?s=&threadid=102273&highlight=b7+threaded+rod

BG, really nice work! That's exactly what I'm looking to do! How have they held up?

I was thinking that I should buy a tap and tap the tube myself. I could save quite a bit of $$ but I know it will be a bitch to do.

Thanks for the pics and let me know how they've held up and to what!

-Jack

Hey Pig, looks like your hand taps page is dead...

I dont know how they hold up in this application, but I do know that I use them at work all the time, and if they are properly lubricated, they will last for a very long time. Like I said in one of those above links: I run the nuts down on those studs with a 1.5" air impact. The studs and nuts are strong. No doubt.

Yes, thats a very different application than 4x4's.

Poly bushings are not evil. They work fine for those of us who haven't succumbed to the marketing scam of "Unrestricted Articulation"

whats it going in?

"Project Freak" (http://www.alaskaoffroad.com/cgi-bin/ikonboard.cgi?s=3e27b4132596ffff;act=ST;f=3;t=16)

http://www.alaskaoffroad.com/cgi-bin/iB_html/uploads/post-3-28901-Nostrils_2.jpg

The front has the threaded B7 rods, the rear however, does not use anything other than poly bushings. No heims, no JJ's, no threaded rods.

Originally posted by bgreen


Poly bushings are not evil. They work fine for those of us who haven't succumbed to the marketing scam of "Unrestricted Articulation"



bgreen, that was excellent!!!!

Can I quote you on that???;)


BTW, one way to remove play in the threaded joint would be to use these: http://www.rctek.com/fixings/bellville_washers.html

EDIT: Obviously in a more appropriate size. Only now did I see that my Google searched example for "bellville washer" was for RC cars...:p

Jack,
I know you say you've already got tube but I found an easy way to go for threaded adapters. My control links are 1.75x.25 DOM. I also have a couple of sticks of 1.25x.280 DOM for steering setups. You can take a 1.5" piece of the 1.25 and tap it for 3/4 rod ends and press it in and weld it to the 1.75" control arm. Also, do you need adjustment at both ends? I'd say use the bushing assembly on one end welded to the tube and use rod ends on the other end for adjustment. Seems ok to me
Rob

Originally posted by IronBenderII
Piggy, RE joints break the bank $35 ea plus tube adapters. But I dig the new allthread. Perhaps rather than use a bolt, use that althread instead... I can run it up further in the tube and get more spot welds in for a better hold. What grade is it and how long of a piece do you get for your $15.


That equates to $91.00 a link (roughly) Now if that is breakin your bank you may want to revaluate your situtation. If you try and cut too many corners your life may be in jepordy.

Originally posted by IronBenderII
Hey Pig, looks like your hand taps page is dead...

Yes, I know the site is kinda fuct right now. I'll see what I can get done this wekend.

Pig, re-evaluate my situation? You're talking $400 as opposed to my $150. I have no job, a mortgage and three kids to feed for up to a year on savings alone (the bone that unemployment throws is barely enough to keep the power on). If I can save $250 on this little piece of the project that is a big savings. I'm also going to use HREW over DOM on the cage. BTW, that $250 wwould pay for my cage. I don't know if you've ever been unemployed in a marked such as this but re-evaluating my situation is all I have time to do. Thanks for the advice.

Rob, I only need adjustments on one end (that will keep me from having to worry about them unthreading on the road). So I like your idea. If I can cut the number of rod ends inhalf that would help out quite a bit especially if I can thread them myself. So when they talk about a 1.25" bolt, that is to the outside of the threads not the inside right?

-Jack

XMR/XML rodend, 40kpsi for $18 at www.qa1.net
Daystar M02153 spring bushings $2 each at http://www.ultimate4wheeldriveperformance.com/
Tapered spacers BRP721 5/8" dia 1/2" width $1.10 each
http://www.cmwraceparts.com/Chassis/Chassis17.html

So 4 rod ends $72
8 bushing $16
8 spacers $9

Get a chunk of either 1.5" schd80 pipe for the bushings, or 2" .25 tube. Tube for the links, depending on size you might or might not need inserts, and away you go. Without bootie fabbing like your are from OZ.

Good find on the spacers, but I can't seem to find anything on that webpage about those $2 bushings. Maybe I'm an idiot. Is there a certain application it comes from? Thanks

Forgot about that. His page sucks, I think thats woodys fault.:D Give him a call, or call who ever and ask for Chevy truck spring bushings...I think that the app for that part number.

I am way late and it might not help but I will post anyway. Like I said I have right about 20,000 miles on my front suspension under a fullsize truck. I run a paralell 4 link with panhard. My links don't seem to be sloppy at all and they are not noisy. However I am sure they won't last forever but I have 2 years on mine towing the work trailer every day so i can't complain. Hope this helps someone!

I have friends who make the front lower control arms for their XJ's that incorporate the 1.25 inch bolts with the head ground then pressed and welded into one side of the arm and the nuts (2 or 3) spaced just right and ground, pressed and welded into the other half of the arm. They have been running these arms on nearly ten or more XJ's all running 35 - 39.5 inch tires for close to a decade in some of the trucks, very close to 100k miles on some of the trucks. I have seen them work in moab, hammers, and the rubicon with no problems. If done right it is far stronger than the stock control arms and they do twist well. I have seen how they are built and would not feel at all concerned about building something similar for my vehicle.
Michael.