Flexing the 3 link (3 Viewers)

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Had wristed arms in the past did not seem help much at all if any:meh:

Like these?

IMGP0514_zps0be72a86.jpg
 
That's pretty sweet. I did a 3 link on my 80. My roommate is going to transplant his 96 cummins into his 60 and wants me to help him link it/build it. Maybe I'll push him towards their arms, that'd be cool too. Might be easier to package without an upper link. Exhaust is going to be a nightmare for me.
 
Those Battlement fab arms are sweet. Looks like a nice kit, priced well too: http://www.battlementfab.com/Radius-Arm-Kit_p_8.html

So in my simple-minded view, these seem a lot better than a 3-link. Better handling I would guess, crazy flex and no 3rd link to set up and fab. I must be missing something. What's the downsides of these arms?

I like that you don't have to make changes to the coil/shock towers either like in 4WU's kit...
 
Radius arms unload on climbs, 3-link is generally considered to be superior.
 
Those Battlement fab arms are sweet. Looks like a nice kit, priced well too: http://www.battlementfab.com/Radius-Arm-Kit_p_8.html

So in my simple-minded view, these seem a lot better than a 3-link. Better handling I would guess, crazy flex and no 3rd link to set up and fab. I must be missing something. What's the downsides of these arms?

I like that you don't have to make changes to the coil/shock towers either like in 4WU's kit...

They still bind and require compliant bushings to flex. Most people that wheel them report that the bushings get chewed up pretty rapidly (a lot of cheaper Jeep lift kits use y-link based radius arms so you can read about them on other forums). They aren't as flexy as a properly designed 3 or 4 link. Unloading on climbs, etc.

You'd still have to weld brackets onto the axle so what's the big detraction from just welding one bracket on the axle and one on the frame and having a 3-link?
 
Radius arms unload on climbs, 3-link is generally considered to be superior.

They still bind and require compliant bushings to flex. Most people that wheel them report that the bushings get chewed up pretty rapidly (a lot of cheaper Jeep lift kits use y-link based radius arms so you can read about them on other forums). They aren't as flexy as a properly designed 3 or 4 link. Unloading on climbs, etc.

You'd still have to weld brackets onto the axle so what's the big detraction from just welding one bracket on the axle and one on the frame and having a 3-link?

Good to know - wasn't aware of the unloading issue with a radius arms since all I know is the 80.

Well it seemed like that radius arm setup was less guesswork to install. With a 3 link it sounds like you really need to get the geometry right, take into account the angles/lengths of everything relative to each other. I always hear people say "a properly set up 3-link is superior, handles great on the road" etc etc, which led me to conclude a lot of people do it wrong and end up with a hackjob that handles like crap...
 
Good to know - wasn't aware of the unloading issue with a radius arms since all I know is the 80.

Well it seemed like that radius arm setup was less guesswork to install. With a 3 link it sounds like you really need to get the geometry right, take into account the angles/lengths of everything relative to each other. I always hear people say "a properly set up 3-link is superior, handles great on the road" etc etc, which led me to conclude a lot of people do it wrong and end up with a hackjob that handles like crap...
On the axle end, for the most part, a taller link tower will be better than a short one, but you need ot make sure that beyond just travelling up and down, that the tower doesn't jab into stuff left and right under articulation. So something on top of the pumpkin will likely be fine.

The frame end will likely be on the inside of the frame, slightly forward of the LCA mounts and above them (slightly). Model it with your best guess, weld it, and rock out.
 
Model it with your best guess, weld it, and rock out.

Heh - see that's what I thought you shouldn't do! If I'm under the truck I can easily visually where to grind stuff, eyeball where to put brackets and links, how to see if there would be clearance issues and whatnot. But then you hear stuff about link calculators and degrees and angles and antiroll squatdive and antisquat and antidive and center rolls and roll centers and then I'm just like f#@k I'll go buy a new LED light bar after coming to the realization I'm just not cut out to do any suspension fabwork.

:)
 
Heh - see that's what I thought you shouldn't do! If I'm under the truck I can easily visually where to grind stuff, eyeball where to put brackets and links, how to see if there would be clearance issues and whatnot. But then you hear stuff about link calculators and degrees and angles and antiroll squatdive and antisquat and antidive and center rolls and roll centers and then I'm just like f#@k I'll go buy a new LED light bar after coming to the realization I'm just not cut out to do any suspension fabwork.

:)

You shouldn't just randomly hack and weld without any concern for those things, but you also shouldn't overthink it because you can't really properly calculate AS/AD without knowing the true COG anyway. Will it be perfect right away? Probably not, but it may be close enough that you don't need to redo it. Engineer in some adjustability (+/- 1.5 inches around your modelled ideal in the vertical axis at the frame with 0.5" increments) and I'd be willing to bet you'll be happy with one of those options.

Until you realize the factory 80 axle has other limitations that make it not worth it
 
I didn't touch the link calculator.

I hadn't built a link set up before but in all my research I decided on a lower length (34" + tube inserts and joints) and an upper about 70% (26") of the lowers. Decided I wanted barnes enduro joints, 2" .25 DOM upper and lowers. 1.5" .25 DOM panhard with 3/4 - 7/8 heims, from Barnes. Chose my mounts. Eyeballed it all into place, upper link on truss, gave it plenty of separation at axle side and I gave it about half of that on the frame side. Gave it some triangulation. They're long and flat. Flexes well. Still working on everything else, cummins and all. So basically I just followed the general rules... I have no concerns it'll handle how I want it to.
 
It would be VERY hard to fxxx up AS/AD enough to make a vehicle drive like s***(look at a short arm tj on 6" coils). However, you can crucify its roll centers and make it extremely annoying, if not, unsafe.

I guess nobody hears these things and rpmo, myself and krazytoy are the only ones with fxxxedupbecause theyrelifted80s?

Can the radius arm talk stop? Its a 3 link thread, btw:) you guys are chasing ghosts with the dozen different versions of them.

Forks are for eating dinner, not propelling trucks. :flipoff2:
 
Challenge:

SurfNturf 2014. Bring your radius arm craziness and ill bring my 3 stink. We will play follow the leader with random naked females driving our trucks over various terrain at speed.

When the radius arm girl fails, she gives me a blowjob. If my 3 linked truck fails, ill give the owner a gagging blowjob(complete with reach around and ball cupping).
 

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