2 link question

[RSR]

Advantages and disadvanteges of a 2 link setup with rubber bushings (like Autofab's) offers. The only ones that I have set up in the past for long travel have had heims. We spend hours cycling the suspension getting the mounting points correct so that there was no preasure on the bolts at any point in the suspension travel. However when we attempted to articulate the axle, the articulation was limited because of the twist of the axle as it moves. This was actually advantageous because that particular bronco was way tall because the owners wanted it way. Owners gripped because the bronco was tippy ('73 race bronco). I reminded them of the conversations that I had had with them about the extreme ride height going into the build.

Anyway, I have noticed that Autofab's 2 link is angled out slightly. That seems to me that it would further cause binding during articulation. I have put Autofabs 2 link on vehicles where articulation and long travel was not an issue, and the traction and handling of the vehicle especially under acceleration was greatly enhanced.

I am building a '93 bronco with custom Deaver race springs (huge free arch). Jeff at Deaver did not want the springs to negative arch without a 2 link. You guys that hammer the crap out of your bronco's, what is your view of the 2 link? Is it worth the effort? Can you describe the driving affects with and without the 2 link? Is the binding of the 2 link under articulation more damaging to the springs than not having them?

Thanks in advance

Rusty

[PaulW]

Advantages and disadvanteges of a 2 link setup with rubber bushings (like Autofab's) offers.
I am building a '93 bronco with custom Deaver race springs (huge free arch). Jeff at Deaver did not want the springs to negative arch without a 2 link. You guys that hammer the crap out of your bronco's, what is your view of the 2 link? Is it worth the effort? Can you describe the driving affects with and without the 2 link? Is the binding of the 2 link under articulation more damaging to the springs than not having them?

Thanks in advance

Rusty

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Deaver said that because he sells a very flexy spring. Follow his advice. Angles and length is just geometry. Make it so it will go together at full compression and full droop. Use Poly bushings not rubber. Stiffer springs would not need the link as proven by the Chris W Bronco.
Leaf springs sag and break due to to much flex. No solution for that issue. For sure its not the extra link. Just keep funds avaiulable to relpace them as required.
PW

[philofab]

The springs live longer with a 2 link because the axle wrap doesn't fatigue them. I will be doing mine soon with a hiem on one end and a poly bushing on the other. Angling the links towards the center helps with roll understeer and keeping the axle centered. I have never worried about articulation.

[gunit]

I have the set up that you described; Deaver race packs and a heimed/poly two link that is set at an angle.

The difference in performance is huge; no more wheel hop in the sand, reduced sway, flatter conering, better weight transfer from side to side and more traction in general.

I go about 3000 hard prerun miles between rebuilds on the springs now. I usually break a spring at the end under the double wrap. When I raced stock full using the same springs, I would go about 1000 race miles between rebuilds and usually broke a spring at the axle plate. This may have been due to the negative arch or the axle wrap (or both).

So, in my experience the springs last longer and the difference in performance is worth the effort alone.

[tcm glx]

Hey Philo,
I remember you had cautioned me to stay away from heims on both ends, well Keifer convinced me otherwise, and I have had zero vibration issues. It rides completely quiet, like it did prior to the 2 link.


As far as my thougts, I just recently added the two link, and I feel much less wheel hop and axle wanting to wrap since I have done this. Other than that, no issues to report.

[philofab]

Hey Philo,
I remember you had cautioned me to stay away from heims on both ends, well Keifer convinced me otherwise, and I have had zero vibration issues. It rides completely quiet, like it did prior to the 2 link.


As far as my thougts, I just recently added the two link, and I feel much less wheel hop and axle wanting to wrap since I have done this. Other than that, no issues to report.

Just they way I build stuff. I'm not saying my way is better. Usually heims transmit vibrations from the axle to the frame... if you ever lose a bearing or u joint you will know it way ahead of time!!!

[RSR]

Thanks to all for your input. One things for sure. They are a lot easier to build and get to cycle correctly with hiems than with bushings. Or...maybe it's just that instead of hours at a time, I just get to work on this stuff a couple hours a month now.

[SteveG]

gunit nailed it. It really is a great upgrade. It makes a huge difference on and off-road.

To add to Dave's comments, I've driven my truck off-road with and without the 2-link bars and the truck feels waaaay better with them.

Without them I can still drive pretty damn fast over stuff, but it feels like you're skipping over bumps and holes and it feels choppy. With the bars, most if not if not all of the choppiness is gone. Instead of bouncing over bumps you can feel the wheels dropping out and actually rolling over the bumps... much smoother, much easier to drive.

Articulation doesn't seem to be a problem. The rear end articulates more than in the following pics. I only stopped because the front wheel came off the ground if I went higher.

[PBR]

mine isn't a 2 link it is a y-link. i has a heim on top of the pumpkin and then y's up to the frame on each side with poly bushings. i think it works very well.

[BajaBronco13]

Hey Steve,

I haven't reached out to John at Autofab yet but do you know what his 2 link retails for?

Chris

[Nick]

Hey Steve,

I haven't reached out to John at Autofab yet but do you know what his 2 link retails for?

Chris

Last time i talked to him, it was going for $400.

[Broncodawg]

Has anyone engineered a two link for EBs? John @ Autofab?
Can only imagine how much better my rig will do in sand.
If going rockcrawling, could just remove them for articulation.

[tcm glx]

Hey Steve,

I haven't reached out to John at Autofab yet but do you know what his 2 link retails for?

Chris

Last time i talked to him, it was going for $400.

Sounds about Right, Keifers kit was right around that price as well, but he runs his with Heims.

[SteveG]

Mark's is more due to the cost of the heim joints.

[PaulW]

Has anyone engineered a two link for EBs? John @ Autofab?
Can only imagine how much better my rig will do in sand.
If going rockcrawling, could just remove them for articulation.

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Why would the links restrict articualtion? The links control axle rotation - not deflection.
PW

[yogib]

Hey Steve.What rear springs are you using? Looks like it flexxes well.Are they the 3" wide Deavers or Nationals.Ive heard its best to stick with 3" wide if you're leaving the rear top on most of the time and it is street driven alot.2 1/2" wide for race vehicles that are lighter and not running the rear top.Just what Ive heard.

[Broncodawg]

Why would the links restrict articualtion? The links control axle rotation - not deflection.
PW

Was referring to more extreme articulation needed in rockcrawling.
Hard to believe it wouldn't atleast limit it some at extreme droop or compression. Everything is a tradeoff tho and axle wrap gets the suck, so like to try them.

[SteveG]

Hey Steve.What rear springs are you using? Looks like it flexxes well.Are they the 3" wide Deavers or Nationals.Ive heard its best to stick with 3" wide if you're leaving the rear top on most of the time and it is street driven alot.2 1/2" wide for race vehicles that are lighter and not running the rear top.Just what Ive heard.

My rear springs are from Autofab. They're 3" wide... I don't know who made them for Autofab but I'm super happy with them.

Why would the links restrict articualtion? The links control axle rotation - not deflection.
PW

Was referring to more extreme articulation needed in rockcrawling.
Hard to believe it wouldn't atleast limit it some at extreme droop or compression. Everything is a tradeoff tho and axle wrap gets the suck, so like to try them.

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.

[PaulW]

[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.

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10 4 Steve
Exactly They present no articulation restritcion when they are built correctly.
The ones I sold Brian were cycled max and min with the link removed and I could install the link in both positions, slightly tight compared to ride height.
PW

[yikes]

...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.

The slight misalignment is why I think a bushing in at least one end is advisable. Something has to compensate for the flattening of the spring as it compresses. The forces on the 2 link, springs and u-bolts seem like they would be quite high with just the smallest misalignment when using heims. I realize many are and have been quite successful using heims, but the mechanics of a solid link and a flexible link just don't pencil out. Has anyone actually engineered a 2 link with FEA testing? I would be very interested in the results.