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Discussion Starter #1 (Edited)
I built a rear triangulated 4 link setup on my YJ about a year ago. For the most part it's been great off-road but on road is no better than leaf springs. I can live with that but what I can't understand is why the Jeep will sit at a certain height in the garage but after hitting a bump it stepping on the bumper, the shocks don't want to come all the way back up to ride height.

I've got 14" Fox coilovers with the remote reservoir. At ride height, I'm sitting 9" in the travel of the shock. My Jeep is pretty light and my springs were initially 95lb and 80lb springs and it rode level. I bumped that up to 110/80 and then 110/95 but it still won't come back up if fully compressed. I've played with the dual rate nuts so that the Jeep would sit on the lower spring at ride height but still nothing. The shocks are pumped up to 200psi as per Fox's recommendation.

Should I be trying stiffer springs still or try playing with the rebound washer stack? I've got the compression settings off the scale on the low end and it's still harsh hitting a bump.

Pictures are really just to show the Jeep because.... Who doesn't like pictures?


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All shocks other than air shocks function as a velocity-dependent force opposing movement. Shock dyno charts have shaft velocity typically as one axis. Unless something is bent, it shouldn't have any impact on the static ride height.

Air shocks have large diameter shafts (as much as 1.5" diameter) which creates a significant defacto spring. The fox through shaft steering damper is an example of a design to eliminate that effect. While the 0.75" shaft in the Fox shocks is larger than a typical oval track or road racing shock, it still won't be that significant and would be constant for a given compression.

I would pull/disconnect the shocks and check that the suspension has full movement and inspect the shock shaft and body for a bend or dent. Typical things that can cause a non-linear response.

Some videos that are interesting, but don't affect the problem:



 

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Discussion Starter #4
Yeah I did a lot of researching when building this setup so I'm familiar with all of those videos. Maybe this video will show what I'm talking about... This is more of an RC car or mountain bike type problem but seems more like it's "shock stiction" meaning that the internal resistance in the shock seals is greater than the forces acting to return it to normal. In my case, we're talking 60lbs of upward force (luggage scale) on the rear bumper to return the Jeep from squatted in the rear to normal ride height. Considering most people who own TJ's say that 200/200 lb springs are the way to go and I'm running 110/95 springs, the forces acting on those Jeeps both up and down is significantly higher than mine when compared to the internal resistance of the shock.

The shocks are straight and smooth when going through the travel without any pressure or springs installed.

It starts at normal ride height and will sit there until any forces act on it. When I push it down, it will stay there as well until something acts on it. You may have to pick a spot on the wall to reference the bumper height when I push/pull it.
 

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Discussion Starter #6
If you post on pirate4x4.com the same question, I’ll respond with a real answer
So that's the second comment about pirate4x4.com. What happened to pirate4x4 that people still read and comment but refuse to help?
 

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So that's the second comment about pirate4x4.com. What happened to pirate4x4 that people still read and comment but refuse to help?
I’m not giving any more tech to this site. The owners suck maple syrup and moose balls.

I’d rather contribute to a better site.

That said, I still read some and troll over here, spreading the word about the new and better one, that feels/is more like the old pirate.
 
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