Topic: 4 link suspension on YJ

[DiGGeR77]

This probably belongs on Member projects, but I never got a answer with a previous post.  I'm highly considering installing a 4 link rear suspension on my yj. I've been tossing around the SUA, SOA upgrade, but the whole 4 link looks like it would solve all the problems. It would give more flex, smoother ride, I wouldn't have to mess with the whole 'track bar' issue to make it pass inspection, parts are relatively inexpensive, doing coil or coil over would be the only big expense. Fabrication isn't a problem, and heck I'm already doing an axle swap, what better time? I was going to keep the front SOA for now (i think). Please comment on this post, if you know anything (pro's or con's) about 4 link setups!

[FourbangerYJ]

4 linking will cost more than you realize. Good joints, tubing, threaded rod ends, brackets, coils or coil overs it all adds up.
Getting the geometry correct can be a problem too if you have not done this before.

[aw12345]

Would it not be better to 4 link the front? Seems like most people like a lot of flex up front, keeps it from getting tippy. You leave the front with springs it will rock from side to side a lot, you kinda want to try to get eaqual flex front and rear so the body stays fairly level IE doesn't roll side to side to much while the axles follow the terrain.
Atleast that was my goal and after a bunch of work and some add ons it actually does pretty much just that
Still want to add a currie rear anti rock swaybar and that's it for my little put put.

[Jeffy]

I've seen some older Jeeps running SOA front and 4-link rears.  They produce 70-80% of the total flex from the rear as a result.  They look sort of awkward.  I think the prefered setup is to have a bit more flex from the front so the tires can pull the rear up.  There are a few DIY weld-together kits out there.  I think Gen-Right has one.

Like what FourbangerYJ said, getting the geometry straight is key and not easy.  Screw it up and your suspension will try to eat itself.  Some use CAD then build a small model before going to the real thing.  It's really a case of measure twice, cut once as parts are expensive.

Still, it's probably the ultimate suspension out there.  Although I would not discount a custom set of SUA leafs, a SOA setup or some combination of both. (front SOA/rear SUA).  Custom leafs will make a HUGE difference as they are built to your Jeeps specific needs.

Now, if you really wanted to link the rear, I'd consider chopping out the frame at the rear then constructing a new rear frame with tubing.  This will give you a flat area to work with.  Also, consider that the rear will really limit how big of a coil-over you can use.  Most of the time it's best to cut holes into the frame and add hoops to allow for the proper length coil-overs.  Otherwise you'l have to run the coil-overs further forward to run a triangulated setup or some combination.

For research, check out http://www.pirate4x4.com.  The forums there are not really noob friendly so do a lot of searching.  If you do your homework and ask appropriate questions, you should get some really helpful info from them.

[Bounty Hunter]

I think it'd be easier and perform better to link the front, the frame is narrower and coilovers can be outside the framerails.  Keeping the rear slightly stiffer than the front will make a more stable and predictable jeep offroad.

[Jeffy]

I think it'd be easier and perform better to link the front, the frame is narrower and coilovers can be outside the framerails.  Keeping the rear slightly stiffer than the front will make a more stable and predictable jeep offroad.

I agree.  This is the premise for the SOA(front) SUA (rear) setup that many people as well as I run.

[FourbangerYJ]

What type of wheeling do you plan on doing?

Can't you just put the track bar back on before your inspection then take it off afterwards?

[Mr_Random]

I agree.  This is the premise for the SOA(front) SUA (rear) setup that many people as well as I run.

Does soa allow more axle flex than sua?

How does the YJ frame compare to the TJ frame? Simplest solution (if it works), would be to chop off and swap over TJ components and use an XJ HPD30, methinks, But that isn't necessarily the best solution for flex and lift height.

[FourbangerYJ]

Does soa allow more axle flex than sua?

Yes, since you use a flatter spring. Less arch = more flex.

[jfrabat]

In my opinion, the nice thing about leafsprings is the simplicity; if you move to 4-link, yes, you will have better flex, but you will also open a whole can of worms.  Are you sure the extr flex is worth all that complication?  If it is, go for it, but if not, think twice before starting that project.

[DiGGeR77]

What type of wheeling do you plan on doing?

Can't you just put the track bar back on before your inspection then take it off afterwards?

Well here in pennsylvania, we got greasey clay, hills, hills, hills, deep creek beds, fallen trees, slate dumps with huge was outs, and the rock crawl'n we do have is wet and slimey! I thinking on doing SOA front and back, then once complete (and my funds replenish) I'll use that for my ride height and convert it to 4 link front and back. That way i don't waste money on lift springs or beafier springs, I'll be able to get all the bugs out, before I get more problems from the 4 link. Does that sound like a good idea?
Will taking off the trackbar with stock springs running D44 & 35's be a problem? I'm fairly sure I got new stock springs om my jeep.

[Jeffy]

Seems like it will be a waste if you go SOA then go to link front and rear.  Really though, if you're going to go through all that trouble, sell the Jeep and build a buggy from scratch since that's what you'll end up with eventually anyway.  I've seen many friends chop up their Jeeps till nothing was left then sell the junk and build from the ground up.

[FourbangerYJ]

Well here in pennsylvania, we got greasey clay, hills, hills, hills, deep creek beds, fallen trees, slate dumps with huge was outs, and the rock crawl'n we do have is wet and slimey! I thinking on doing SOA front and back, then once complete (and my funds replenish) I'll use that for my ride height and convert it to 4 link front and back. That way i don't waste money on lift springs or beafier springs, I'll be able to get all the bugs out, before I get more problems from the 4 link. Does that sound like a good idea?
Will taking off the trackbar with stock springs running D44 & 35's be a problem? I'm fairly sure I got new stock springs om my jeep.

If you do SOA F&R make sure you put on a antiwrap bar on the rear. You will toast the springs and driveshaft U.J's in a hurry.
Personally I would not link it. I love my leafs. I am not running trackbars or swaybars. I have not for years and years, I drive it everywhere. Not a single problem or concern. Not sure if you needed them for your state inspection.
Many people run the stock springs SOA. They don't last long unless you add a extra main leaf. Since you only want to run 35's the stock springs should give you plenty of lift to clear them. The Full Traction zero lift springs look good too. I don't know of anyone running them but they look like a nice spring. But the best leafs are the custom ones Deaver or Alcan.

[Bounty Hunter]

Leaf springs flex pretty good, and they're stupid simple.  KISS is good.  I run stock leaf packs plus an extra main leaf SOA.

[FourbangerYJ]

Leaf springs flex pretty good, and they're stupid simple.  KISS is good.  I run stock leaf packs plus an extra main leaf SOA.

Looks good. 
I agree with keeping things simple!