2 link question

[magic carpet XLT]

is it really worth the time to do FEA on a 2 link leaf spring setup? why not just 4 link it...i know class rules are class rules, but if you are taking it that seriously you should look for a better solution than leafs.

i'm going to give a stab at a 2 link, i don't think it will be that bad rock crawling. links will need to be burly material, but i have never hit the approach side of my springs, just the departure side. the problem with the wrap bars that most crawlers run is that they don't take into account the change in suspension dynamics it will create, they only see the benefit of no pinion wrap. a lot of people put them on the wrong side and end up getting goofy acceleration or braking characteristics (amplified by the extreme angles of crawling).

[Broncodawg]

For a rock crawler I think the hindrance would be ground clearance issues and not binding issues. I checked the geometry on my 2-link kit when I installed it by removing and installing the bars with the suspension fully compressed and extended. Everything aligned very well in either direction. At the extremes there was some misalignment (just as John said there would be) but, surprisingly, it was minimal.

I stand corrected and glad to hear they work that well.
Ground clearance is an issue, but being close to the wheel/tire, won't be a problem all that often.

Thanks.

[cs_drums]

Who has done it? How Long are your links? Is it worth the extra time and money?

[AussieRod]

if you are refering to the 64" leaf springs, because they are spring under, a 2 link isnt really required.

[Polarcub]

As rod said in theory you should not need a 2 link set up with the spring under but with that said.....In the other thread there was a pic of a spring under with a 2 link,
Is it worth it really depends....you kind of need to see if your set up is experiencing axle wrap if it is then yes. As far as design goes the length of the links will depend on how it cycles IMO if you are spring under it is not worth it time/money wise, I would not plan on a 2 link with this set up at the start....I have not run a two link or spring under so I am a bit out of my knowledge base here though, one exception that may change my mind is if you are going to be pushing GOBs of HP to the rear then maybe it would be something I would build at the start. Otherwise I would see if you need it

[AussieRod]

As rod said in theory you should not need a 2 link set up with the spring under but with that said.....In the other thread there was a pic of a spring under with a 2 link,
Is it worth it really depends....you kind of need to see if your set up is experiencing axle wrap if it is then yes. As far as design goes the length of the links will depend on how it cycles IMO if you are spring under it is not worth it time/money wise, I would not plan on a 2 link with this set up at the start....I have not run a two link or spring under so I am a bit out of my knowledge base here though, one exception that may change my mind is if you are going to be pushing GOBs of HP to the rear then maybe it would be something I would build at the start. Otherwise I would see if you need it

This too

[kylesgorter]

2links by design will bind at a given amount of movement. im not a big fan of them at all and perfer an upper wishbone instead.

You wont be able to make a 2link that will support the 18+ inches the 64in packs will make especially if they are the g2's. Matter of fact, i highly doubt you would even be able to get a wishbone to work at that amount of extension without bind. The ONLY way the autofabs can kind of work is through the use of bushings, but even then they can do maybe 15in before the binding gets bad. Autofab says they work with their 18" travel springs (highly doubt those make 18" anyways) but I just dont see them being capable of going to that much extension and not causing a problem.


Also, want to add here that just because its spring under doesnt mean it wouldnt benefit from some sort of device that limits wrapping. ive built two trucks with 64 g2 packs and both have very noticeable axle twisting that we have even tracked with the go-pro. Its not as much as most setups but very obvious to see

[ryan B]

mine cycles 19.5, and i've been running the same 64's for years. without the links there was a ton of axle wrap on my truck, and it would mess up driveline u-joints.

[tcm glx]

2links by design will bind at a given amount of movement. im not a big fan of them at all and perfer an upper wishbone instead.

You wont be able to make a 2link that will support the 18+ inches the 64in packs will make especially if they are the g2's. Matter of fact, i highly doubt you would even be able to get a wishbone to work at that amount of extension without bind. The ONLY way the autofabs can kind of work is through the use of bushings, but even then they can do maybe 15in before the binding gets bad. Autofab says they work with their 18" travel springs (highly doubt those make 18" anyways) but I just dont see them being capable of going to that much extension and not causing a problem.


Also, want to add here that just because its spring under doesnt mean it wouldnt benefit from some sort of device that limits wrapping. ive built two trucks with 64 g2 packs and both have very noticeable axle twisting that we have even tracked with the go-pro. Its not as much as most setups but very obvious to see

I'm going on 3 yrs with a 2 link that has heims on both ends..... No binding, no broken leafs, no issues to report. Strapped at 17.5" of travel. So I'd say your statement about Autofabs working ony because it's bushing mounted is off.........

[cs_drums]

Ryan B,
How long are your links eye-eye?

[kylesgorter]

how long are the links?

which spring packs do you have?

did you build it?

Binding can be absorbed through the leaf springs by forcing them to arc but only so much as it is a fore/aft load. Have you ever sheared or broken a centerpin on the leaf packs since youve had them?

Theres lots of 2 link setups running around without much issues Im sure but doesnt make the DESIGN correct. Gotta wonder why ford would put a slip spline rear driveshaft if it wasnt needed....

[kylesgorter]

On a bronco with j40's and an autofab 2 link I noticed binding beginning at 12-13in but the bushings did allow it to go to almost 16in but that was about it for those springs. Ive set up two broncos with j40's and the one without the 2 link rode, drove and overall worked much better than the other. Though he also has 16's through the floor and the 2 link one had 12's under the body with a shock hoop. The one with the 2 link is now gonna be a 4 link..

[kylesgorter]

Oh, and the 64's are pretty much a whole different ball game than any spring over bronco pack setup..... I remain skeptical even after reading the entire other thread.

[tcm glx]

how long are the links?

which spring packs do you have?

did you build it?

Binding can be absorbed through the leaf springs by forcing them to arc but only so much as it is a fore/aft load. Have you ever sheared or broken a centerpin on the leaf packs since youve had them?

Theres lots of 2 link setups running around without much issues Im sure but doesnt make the DESIGN correct. Gotta wonder why ford would put a slip spline rear driveshaft if it wasnt needed....

Southwest performance 2 link
Running f53s
Never broke a center pin
I have dropped out several times messing with the other things, and no bind.



I put somewhere between 5-7k miles a year, been running this setup for over 3 years. Plenty of off road miles with no issues at all.

[kylesgorter]

Interesting... I dont doubt the work from mark at all. if it works, then it works plain and simple. I havent actually messed with any f53 springs on broncos just j40's and g70. if you can easily pull the bolts out with it all the way drooped then the proof is in the pudding

With the 64's, the springs have tons of arch even at ride. All the bronco spring over setups Ive seen, the springs dont have nearly as massive arch while restig at ride height. The pinion as well as the driveshaft length changes considerably more (though still workable) with the spring under configuation as the spring flattens out. The 64's are capable of massive amounts of movement and incorporate a lot of really different geometry than the standard type packs.

[only1mikey]

Kyle,

I think extending and plating up all those stock cast ranger beams has your brain fried a bit.

A two link can work perfectly fine IF you set it up correctly. You can't just make the link any lenght you feel like and you can't just mount it anywhere it fits. Autofab and Mark both have it figured out, so it obviously is possible.

Also, what's skeptical about the GIANT 64 kit?

Mike

[AussieRod]

Kyle,

I think extending and plating up all those stock cast ranger beams has your brain fried a bit.

A two link can work perfectly fine IF you set it up correctly. You can't just make the link any lenght you feel like and you can't just mount it anywhere it fits. Autofab and Mark both have it figured out, so it obviously is possible.

Also, what's skeptical about the GIANT 64 kit?

Mike

Easy there, Mike, Kyle is just trying to understand why we would use these 2 links. Kyle, I have seen both Mark's and AUtofab's 2 links in action, I can tell you that most of the Broncos running them, 16 - 18" of travel is the norm, rather than the exception. Mark uses heims (which personally I wouldn't) and John uses bushings (my preference). As long as the mounting points are correctly positioned, the bind is outside the travel area of the axle. The Giant kit would require careful attention to the slip joint travel due to the lengthening / shortening as the axle travels from bump to full stretch as the arch flattens etc. Obviously, one would map this carefully during assembly to make sure a) the yoke didnt bottom at full stuff, and b) the slip spline didnt pull out at full stretch. No-one is doubting your knowledge here, ok? Geoff has his ideas, others theirs. Geoff makes some good stuff, it obviously works. So do Mark at Southwest and John at Autofab. I guess its just mocha or espresso, which do you prefer? Guys, please lets not turn this into a pissing contest, huh? We GFB'ers respect each others opinions, so be nice.

[ChaseTruck754]

Rod - I can't say for 100% sure, but I think you might be missing some sarcasm in Mike's post. My guess is he knows Kyle & is poking fun a bit. Just like the way others on here poke fun if we know each other.

Still, your point is valid, just not sure Mikey was being malicious with his comment

[Smart Alex]

lol.

so who is the bad ass that can make all this work in a cycling drawing?

[ChaseTruck754]

I'll give you $5 if you can get John @ Autofab to get anywhere near a computer to even think of messing with that. Who needs new fangled mumbo jumbo like computers when your head is the computer!