Darky
NAXJA Forum User
- Location
- 29 Palms, CA
:roflmao:
TNT Y-link = Owned UCA Bushings
- Thread starter MoparManiac
- Start date
Boostwerks.com
NAXJA Forum User
- Location
- Colorado
Dundy
NAXJA Forum User
- Location
- Taunton, MA
niiiiice
- Location
- Reno, Nevada
I did mine 2 years ago I think and its fine.
Thanks, I think I got it now. I can be dense sometimes. I'm not sure Phil's method helped me anyway but it was interesting none-the-less.RCP Phx said:
- Location
- Hammertown, USA
That's not a bad idea. I have RE superflex joints in their place (custom, pre TNT stuff thats out there now) to fix the wearing out bushings.
I've always thought that bolt was a little weak. :/
beakie
NAXJA Forum User
- Location
- Ontario, Canada
was the part # for the WJ UCA bushings ever found?
will be doing this in the near future, would like to add it to the list of mods.
will be doing this in the near future, would like to add it to the list of mods.
Dundy
NAXJA Forum User
- Location
- Taunton, MA
52088214 is the Crown Automotive part number...
beakie
NAXJA Forum User
- Location
- Ontario, Canada
merci.
MoparManiac
NAXJA Forum User
- Location
- Amherst, NH
I spoke with Bob, and yes I believe they use the small RE superride bushings in theirs?
MoparManiac
NAXJA Forum User
- Location
- Amherst, NH
Just FYI, I blew through the pass side WJ UCA bushing in one trail run. However, since the driver side never wears out, I think I have some other issues going on.
Andy in Pa.
NAXJA Member #180
- Location
- Downingtown, Pa.
Colin,
two things--
1. Check to make sure you haven't tweaked the pass side UCA mount at the axle. This is common on D30 axles, and even the slightest tweak will kill UCA bushings quickly.
2. Double-Check the length on your uppers. Make sure they are exactly the same length.
This is an inherent problem with that kit. NHRocker (Rob) has the TNT kit too, and he actually ripped off the pass side UCA mount at NAC-Fest a few years ago. Check the length of the uppers, maybe you can swap in a set of Claytons uppers, or another upper that has a johnny joint on one end....??
If you want to fab something in, there is always Johnny joints (which is what I run, Claytons...), but in my most recent research, it seems that Rock Krawler has the best joints (Krawler joints) right now for strength and rotational clearance.
- Location
- Wasatch Range
The truss comes with Super-ride bushings, so yes.
vetteboy
NAXJA Forum User
- Location
- morganville, nj
FWIW, with radius arms a krawler joint in the UCA spot on the axle won't see a lot of movement, if any. The triangle formed between the links stays pretty rigid.
If you plan on keeping both upper arms, I'd advise against going to rigid joints at all locations...the inherent binding in that radius arm setup isn't so much a rotational movement as it is a 'squishing' of the bushing that allows it to flex. Which is one reason why it tends to destroy that sleeve in the middle fairly quickly (and why it'll tend to rip/tweak the passenger side mount, as it becomes the weak link).
vetteboy
NAXJA Forum User
- Location
- morganville, nj
This is an older post of mine on P4x4, but it kind of addresses the issue here.
I do not have a single bushing on my suspension, anywhere (well, with the exception of the shocks). This is not death, it's not instant catastrophe, and I rather like the way it rides and performs. Lowers run 2.5" Johnny Joints on both ends, uppers run 5/8 x 3/4 heims on both ends, panhard in front has heims on both ends. I can guarantee that I'll never run bushings on any future wheeling rigs I build. There are many more factors that contribute to undesirable NVH levels than running not bushings.
That being said - I would also absolutely NOT run all solid joints on a radius arm setup.
It's a matter of constraint, when it comes down to it. The goal of any suspension is to constrain the axle to a certain range of motion, which for (offroad use) ideally is:
- free vertical travel (within limits of other suspension components)
- free warp travel (articulation, again within limits of other components)
- zero lateral travel (panhard arc excluded)
- zero longitudinal travel (wheel recession excluded)
- zero torque twist (axle wrap)
Put more simply, you want the axle to move up and down, and you want it to flex. Anything else is not a good thing.
The 'binding' that people talk about is an effect of having the suspension "over-constrain" the axle. This happens when the links and/or geometry are fighting each other to maintain the axle in a certain position. A well-designed suspension (for offroad use, anyway) minimizes this from happening.
Case in point: look at a 3-link with panhard. Each link does its job in isolation. The three links that are roughly parallel do nothing to fight the panhard for lateral control. The single upper link is the only thing that controls torque reaction and pinion/caster angle. The two lower links keep the axle located longitudinally under the vehicle. This is what I've got, and even with rigid joints all around, there is NO binding anywhere in the range of usable travel. To get to the point where the joints run out of misalignment, I'm well beyond any possible driveshaft angle or usable travel.
If you look at the factory XJ suspension, it has a certain amount of 'overconstraint' designed into it. The slight triangulation in the upper and lower control arms resists lateral movement, but the panhard forces it through travel. Likewise during flex, the control arms on the right side are trying to maintain a different pinion angle than the control arms on the left side, and the difference is made up through distortion in the bushings (radius arms have this same issue). The big thing here is that the type of distortion in the bushings is not something that a heim or johnny joint can handle. Think of all the ways you can "squish" a bushing, compared to the ways a solid joint can move, and you'll see what I mean. The motion needed to compensate for that binding isn't entirely within the range of motion of a flex joint.
These reasons are why a 3-link with panhard doesn't bind, but the factory 4-link w/panhard does. Or why a traditional radius arm setup binds, but a wristed setup doesn't. By removing that one link or wristing an arm, you're removing that bit of overconstraint, and giving more free motion to the suspension.
So why do things come that way from the factory? That bind that radius arms experience has another effect - it reduces sway. If you think about it, body roll is no different than the axle articulating...it's just a matter of which thing remains stationary, and which thing moves. The Ford radius arm setup and the Jeep 4-link w/panhard are both very stable setups, that are great for going down the road and still offer a reasonable amount of flex before the bushings start to limit it. Neither Jeep nor Ford set out to create vehicles with monster suspension travel; they had to make compromises in order to satisfy the larger market, which is the street-driving population. The aftermarket then gets to address this with wristed Ford arms (think Cage or James Duff), or setups with different geometry (think RockKrawler 3-link for the XJ), that move that compromise away from road manners in favor of offroad ability. Keep in mind that what we consider 'acceptable' or 'pretty good' is much different than the ride quality & performance engineers at DCX or Ford.
So what's the point here? When I had radius arms on my XJ, I used factory bushings on the axle, with a Johnny Joint on the frame side. It was simple, cheap, and got the job done. Would Johnny Joints on both sides have helped anything? I don't think so. It flexed to the limits of the other components, and I didn't risk ripping control arm mounts off the axle from binding. After I got rid of that setup for the 3-link I've got now, I switched to rigid joints all around, because I wanted the best axle control possible, and didn't have to worry anymore about needing bushing deflection to account for binding.
I do not have a single bushing on my suspension, anywhere (well, with the exception of the shocks). This is not death, it's not instant catastrophe, and I rather like the way it rides and performs. Lowers run 2.5" Johnny Joints on both ends, uppers run 5/8 x 3/4 heims on both ends, panhard in front has heims on both ends. I can guarantee that I'll never run bushings on any future wheeling rigs I build. There are many more factors that contribute to undesirable NVH levels than running not bushings.
That being said - I would also absolutely NOT run all solid joints on a radius arm setup.
It's a matter of constraint, when it comes down to it. The goal of any suspension is to constrain the axle to a certain range of motion, which for (offroad use) ideally is:
- free vertical travel (within limits of other suspension components)
- free warp travel (articulation, again within limits of other components)
- zero lateral travel (panhard arc excluded)
- zero longitudinal travel (wheel recession excluded)
- zero torque twist (axle wrap)
Put more simply, you want the axle to move up and down, and you want it to flex. Anything else is not a good thing.
The 'binding' that people talk about is an effect of having the suspension "over-constrain" the axle. This happens when the links and/or geometry are fighting each other to maintain the axle in a certain position. A well-designed suspension (for offroad use, anyway) minimizes this from happening.
Case in point: look at a 3-link with panhard. Each link does its job in isolation. The three links that are roughly parallel do nothing to fight the panhard for lateral control. The single upper link is the only thing that controls torque reaction and pinion/caster angle. The two lower links keep the axle located longitudinally under the vehicle. This is what I've got, and even with rigid joints all around, there is NO binding anywhere in the range of usable travel. To get to the point where the joints run out of misalignment, I'm well beyond any possible driveshaft angle or usable travel.
If you look at the factory XJ suspension, it has a certain amount of 'overconstraint' designed into it. The slight triangulation in the upper and lower control arms resists lateral movement, but the panhard forces it through travel. Likewise during flex, the control arms on the right side are trying to maintain a different pinion angle than the control arms on the left side, and the difference is made up through distortion in the bushings (radius arms have this same issue). The big thing here is that the type of distortion in the bushings is not something that a heim or johnny joint can handle. Think of all the ways you can "squish" a bushing, compared to the ways a solid joint can move, and you'll see what I mean. The motion needed to compensate for that binding isn't entirely within the range of motion of a flex joint.
These reasons are why a 3-link with panhard doesn't bind, but the factory 4-link w/panhard does. Or why a traditional radius arm setup binds, but a wristed setup doesn't. By removing that one link or wristing an arm, you're removing that bit of overconstraint, and giving more free motion to the suspension.
So why do things come that way from the factory? That bind that radius arms experience has another effect - it reduces sway. If you think about it, body roll is no different than the axle articulating...it's just a matter of which thing remains stationary, and which thing moves. The Ford radius arm setup and the Jeep 4-link w/panhard are both very stable setups, that are great for going down the road and still offer a reasonable amount of flex before the bushings start to limit it. Neither Jeep nor Ford set out to create vehicles with monster suspension travel; they had to make compromises in order to satisfy the larger market, which is the street-driving population. The aftermarket then gets to address this with wristed Ford arms (think Cage or James Duff), or setups with different geometry (think RockKrawler 3-link for the XJ), that move that compromise away from road manners in favor of offroad ability. Keep in mind that what we consider 'acceptable' or 'pretty good' is much different than the ride quality & performance engineers at DCX or Ford.
So what's the point here? When I had radius arms on my XJ, I used factory bushings on the axle, with a Johnny Joint on the frame side. It was simple, cheap, and got the job done. Would Johnny Joints on both sides have helped anything? I don't think so. It flexed to the limits of the other components, and I didn't risk ripping control arm mounts off the axle from binding. After I got rid of that setup for the 3-link I've got now, I switched to rigid joints all around, because I wanted the best axle control possible, and didn't have to worry anymore about needing bushing deflection to account for binding.
MoparManiac
NAXJA Forum User
- Location
- Amherst, NH
Thanks man, I think I'm going to double check my LCA and UCA lengths again this weekend before the M&G. Also I think my trac bar might be pushing too far to the pass side. I know my UCA mount is good because it was reinforced before I wheeled it.
Andy in Pa.
NAXJA Member #180
- Location
- Downingtown, Pa.
Yeah thats true, the Krawler joint is a bit of overkill for that application. I do believe though that the UCA should have SOME amount of "twisting" rotational movement built in, more than what a UCA with rubber/poly bushing combo allow. My original Claytons setup had rubber bushings on both ends of the UCA (it used factory LCA rubber bushings on one end, and of course factory UCA bushings at the axle). I didn't have trouble with this setup killing bushings. I am also thinking the angles/forces are a bit different with the TNT setup with the bent lowers. (?)
MoparManiac
NAXJA Forum User
- Location
- Amherst, NH
I've been happy with everything else from the TNT kit...but now I'm beginning to wish I had just went Claytons or RK 3-link.
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