3 link with TnT parts?

So after reading multiple threads about longarm setups, radius arms, suspension binding and worn out control arm bushings, I thought of an idea.

I really like the way TnT has their radius arm setup mounted to a heavy duty belly pan with lots of bolts through the frame and the CA mounts above the bottom of the rails for lots of clearance. However, I've heard of tons of problems with binding, eating bushings, and suspension 'unloading' during butt-clenching moments. Currie makes some nice axle side UCA bushings with Johnny joints, but supposedly you can't use those with a radius arm because of the binding.

My idea is to use the TnT belly pan and long arms as lower arms in a 3-link setup. Then use a RE adjustable upper arm in the stock location for the last link, plus the usual RE heavy duty track-bar. The bushings would be the normal ones on the TnT arms (joints body side, rubber axle side) and the RE upper would have RE superflex joints on the body side and the Currie Johnny joint on the axle side. (BTW: which side UCA do you use on a 3-link?). Currie has a new setup to reinforce the passenger side axle UCA mount and use a johnny joint in either UCA mount. http://www.currieenterprises.com/cestore/Product.aspx?id=1277

Would this idea work? I'm not too intelligent yet when it comes to these crazy offroad suspension setups, but I'm trying to learn. Don't flame me too bad if this is a stupid idea. If this doesn't work, what about running the TnT longarms with both stock uppers for a 4-link? Or would the uppers have to be parallel? :dunno:

Discuss.

IRON ROCK OFF ROAD: XJ Critical Path Long Arm Upgrade Set it up like this system, including a gusset on the drivers side arms.no more binging and a lot less work to do..

Work? There is no work involved in the system I described other than swapping to Johnny Joints on the axle UCA.

I'm not fond of the weak looking crossmember with no skid plate on the Iron Rock or Claytons setup. I also don't like the way Rock krawler has their arm mounts on the bottom of the unibody rails.

The are three big problem I see with your idea.

First is the lack of separation of the frame side mounts. The T&T kit raises the LCA mounts a lot and keeping the UCA in the stock location is going to provide very little distance in the z (vertical from ground) axis. This is going to produce a very high anti-squat (AS) number and cause the suspension to act almost as if it were very stiff under changes in acceleration. IE, it will greatly resist diving under braking and the pull up under acceleration. You want a suspension to resist it, but not to much either, this really plays into personal opinions. To give you an idea, when I built my 3-link I raised my LCA mounts close to where T&T puts theirs and this required me to go through the floor to get an acceptable AS number. This isn't a required case for everyone, though.

The second is that the frame side UCA mount just plain isn't strong enough to support the entire duties of a single UCA mount. I haven't seen one fail in person, but there are quite a few pictures floating around on here.

The third, with that short UCA you'll most likely end up seeing an undesirable amount of pinion/caster change throughout the travel.

Granted all the above those are just numbers, but good theory if you only want to build it once. Keep in mind that everyone is going to like a different setup and the numbers aren't gospel. I've seen a XJ perform in person with raised LCA mounts similar to mine and a UCA mount that didn't go through the floor (but not in the stock location either) and it seemed to work pretty well.

Grab the calculator and read up here there is lots of good 3 (and 4) link information there.
http://www.pirate4x4.com/forum/showthread.php?t=204893
Here is another good link on :
http://www.naxja.org/forum/showthread.php?t=927298

builder said:

IRON ROCK OFF ROAD: XJ Critical Path Long Arm Upgrade Set it up like this system, including a gusset on the drivers side arms.no more binging and a lot less work to do..

Click to expand...

This is NOT what he is talking about. That setup you linked is not a 3-link. Let's not get into a whole which bolt on suspension is better thread here. Please.

On my RK 3 link the third link is on the driver's side. I don't know if that's where it neds to be but that's where it is. I'd imagine the axle end mount is stronger on this side. The arms mounting below the rails is annoying and on my first time out with them, I landed on the arms a few times, drug em over rocks, etc and they held up to it. little scarring, but no damage or bent links or anything.I also like how the mounts bolt to the bottom of the frame as well as through it. I would've preferred something like T&T to mount up high, but had heard too many issues with bushings and whatnot so I went with the RK. Plus they were listed for only $600.

Darky, where does the single UCA mount on the body side? Is that integrated in with the lower mount all in one piece? That has always confused me.

On the new ones, it's all one bracket. The LCA comes off the bottom and the UCA is inside the "framerails". The bracket goes over the fuel and brake lines.

You would almost have to go through the floor on the passenger side for the third upper link in order to get a decent setup as well as clearance. There is not enough room on the drivers side thanks to the driveshaft.

I have the TNT setup and have thought about doing exactly what you're thinking of. I've seen a pic of someone doing it on pirate, and they went through the floor like Bill (RCMan) did. I might do this in the future, or just sell it for a 3 link kit.

Also, I have currie JJs for the UCAs at the axle end. Yes there is more binding but the rear will force it to flex. This is definitely putting more stress on the mounts however, and I do plan on a 3 link by the fall.

MoparManiac said:

You would almost have to go through the floor on the passenger side for the third upper link in order to get a decent setup as well as clearance. There is not enough room on the drivers side thanks to the driveshaft.

I have the TNT setup and have thought about doing exactly what you're thinking of. I've seen a pic of someone doing it on pirate, and they went through the floor like Bill (RCMan) did. I might do this in the future, or just sell it for a 3 link kit.

Also, I have currie JJs for the UCAs at the axle end. Yes there is more binding but the rear will force it to flex. This is definitely putting more stress on the mounts however, and I do plan on a 3 link by the fall.

Click to expand...

I also have the TnT Y-link, and have also pondered the viability of turning it into a 3 link. ^^What he said.^^ With the location of the radius arms, if you turned them into lowers, there really isn't any place that you could put an upper and get a good suspension setup. You would basically have to put it in the middle of the passenger side floor. Stuff is in the way.

I love the belly pan too, but where the mounts are is just not setup to work with a 3 link.

I have no idea what I'm going to do in the future....just deal with it and keep making small corrections, or go a totally different route?? Rides nice and does great on a lot of different types of terrain, just not really steep hairy obstacles. Although, I've seen pics of guys with the TnT go up some crazy stuff that I don't think mine would do.....everyone's jeep is different.

I've heard of people running the T&T minus one of the upper links. Don't know how recommended it is or isn't but it seems to help with the binding problem at least.

I know theoretically there is binding with the Ylink, but I haven't had any problems with it....maybe my axle just twists?? Mine flexes more than anyone could ever need it to. The problem I have is the unloading on steep stuff. It's very scary!!

Here you can watch the front end jump over a good 3' or so due to unloading!! Watch at the beginning, you'll see it just jump.
http://www.youtube.com/watch?v=abGnex71G_E

I have an even better view of it on DVD but I have no clue how to rip it onto a format that I can upload. It was filmed on a digital camcorder that records onto a little DVD taht you can play on the TV. Front end unloads, rear tire hits rock that it would otherwise just go straight over, front end jumps over to one side real bad.

Can anyone link me to a thread showing one of these 3-links with the UCA through the floor on Pirate? I looked at the links provided above and the pics were kind of hard to see what was going on. I'm sure this isn't the best idea for a DD, but maybe I can make something work somehow.

no need to go to pirate

http://naxja.org/forum/showthread.php?t=956040&page=11

this is the page in bill's thread where he decides to go with the front 3 link...lots of great pictures and info.

Thanks, I've read through most of the recent threads in the Fab forum, but haven't kept up with that one. Sucks that I can't see pics at work.

Sounds like he's in the same boat as me. Still wants to keep that upper link as low as possible so he can box and seal in the passenger compartment.

ahh, yeah. I remember when this placed blocked photobucket....that sucks. Definitely check it out when ya get home though, good stuff!! :thumbup: