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Look at that droop! Rock Krawler 4-Link Rear Conversion
Again though... It is as you pointed out. It is complicated by the lateral movement induced by the pan hard. How much lateral movement will be influenced by how flat that bar is before any articulation.
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Panhard bar is 44” long. A conservative 12” shock displacement (producing 14 degrees of axle rotation) for bar with neutral position at perfectly horizontal will result in <2” of lateral movement (1.7”). If the joints can’t freely accommodate 2” of lateral movement (which I don’t think there is that kind of lateral freedom) then the links will bend slightly. This bending stiffness is perhaps the loss in articulation observed.
Panhard bar is 44” long. A conservative 12” shock displacement (producing 14 degrees of axle rotation) for bar with neutral position at perfectly horizontal will result in <2” of lateral movement (1.7”). If the joints can’t freely accommodate 2” of lateral movement (which I don’t think there is that kind of lateral freedom) then the links will bend slightly. This bending stiffness is perhaps the loss in articulation observed.
very possible.... Would hit that lateral limit in the uppers long before the lowers because of the length.
Still not sure about the lateral DOF with the johnies. If there is a freely rotating joint (up to say 25 degrees) at both ends of the links then they will not be able to “bind up” from lateral axle motion and produce a bending response limiting articulation. 
hard for me to believe that <2” of lateral motion can limit articulation. But I guess the real world data suggests otherwise.
hard for me to believe that <2” of lateral motion can limit articulation. But I guess the real world data suggests otherwise.
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I do not know about that "real world data".... In this thread it is one person saying not maxing with the 5 link... I am sure there are others. But my one question to them is how flat was that track bar? If it is further down on the arc I can see it creating well over 2 inch of lateral movement... So then it is how much lateral movement puts those joints into a bind at full flex? How far out of horizontal was the pan hard? I would assume the bind happens faster (with less flex) when the droop is on the passenger side because the movement would be greater than if the passenger side was in compression. assuming the pan hard is dropping from driver to passenger as happens with most suspension lifts.Still not sure about the lateral DOF with the johnies. If there is a freely rotating joint (up to say 25 degrees) at both ends of the links then they will not be able to “bind up” from lateral axle motion and produce a bending response limiting articulation.
hard for me to believe that <2” of lateral motion can limit articulation. But I guess the real world data suggests otherwise.
How loud/drone-y is this in the cab? I did something very similar on my teenage diesel Jetta and couldn’t take it over 60 without vibrating the trim off, but I love short dumps like this.My exhaust is completely homemade, so that might make a difference
It’s better than I was expecting. Cruising on the interstate it almost seems quieter, perhaps due to the lower tone? But under full throttle it sounds like absolute shit inside the cab. Very raspy, if that is even a word that can be used as an adjective.
That said-girly loves it, which is good seems how it’s her rig.
You could pay $40 for a horrible sounding exhaust or go for a “Bronco specific” horrible sounding exhaust for $500. We aren’t exactly doing a budget-friendly build, but some things just don’t make sense to go premium on. All the aftermarket stuff sounds like the Oscar-winning cinematic masterpiece of 2505. (That’s an Idiocracry reference to the movie “ASS”)
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Wild that it’s sort-of quieter. My only complaint is the lack of a deeper exhaust, especially on the 4-banger like mine. Might go crazy with a hacksaw eventually.It’s better than I was expecting. Cruising on the interstate it almost seems quieter, perhaps due to the lower tone? But under full throttle it sounds like absolute shit inside the cab. Very raspy, if that is even a word that can be used as an adjective.
That said-girly loves it, which is good seems how it’s her rig.
If nothing else, weld it back together
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I had the RockJock track bar and bracket, so it was essentially flat. I obviously can't provide any more data as I'm past the point of no return. We'll find out if the 4 link will lift a tire in a similar situation. There are others here that have done the conversion that may be able to provide more before/after comparison data. I don't pick my Bronco up until tomorrow...
I hope it does provide you more articulation... You say you had the track bar and bracket... But what about upper and lower control arms because really... That is where the resistance is at... It is the upper and lower trailing arms that need to be johnny joints to even come close to the 4 link.
For those that had this done at a shop, how many hours did they charge for the 4-link conversion?
Trying to determine if the quotes I’m receiving are reasonable for the fab work and installation.
Trying to determine if the quotes I’m receiving are reasonable for the fab work and installation.
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Yes, I also had the full upper/lower RJ arms with JJs on both ends. You can see the lowers hanging in the first pic.
Well damn... There is bind somewhere then.... Again... I am going to have to find a ramp and play with it a bit to get an idea of what it is.... Andy is probably right.... It is probably the control arms maxing due to the lateral shift. My guess is that it is the uppers.
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