4 linking the rear 89XJ

Ok so iv done some searching and so far out of all the reading not many of my concerns have been answered. most of all i will be doing this on my own with the help of the wonderful itnernet nad forums such this where i can pick the brains of ppl who have done it . im looking for information on how to figure out exaclty there to mount the Long arms to the uni-body iv seen many diff ways but none have said how they came up with mounting them there. i have access to all types of metals i got to school for welding and can fab up anything i want. im not asking to do it for me just where to pull up good info and if you have that good info i would love to hear it. i will be running 38's GM14bFF with a 79 HP dana 60 up front and i really dont want the rear leafs.i know there is alot of work here but im down for it this will not be a DD it will be only trail once done.im sure stuff is missing and in one big paragraph but im tired and at work and help would be greatly appreciated. also i want coil overs not just coils in the rear. thank you alex

pirate4x4.com

yeah i cant search there they have this thing called a membership or red star in order to search the site

You can search it with google.


Go to google and click 'advanced search'.

iv typed in 4 link, coil over, 3-link and i get alot of this is what im doing here it is or this is whats done. im not exaclty sure the technical terms i should be searching for to find out where the links need to be mounted for them to be correct and or how to figure out the length/angle and all that fun stuff.

You may enjoy playing with this.

Four Link Calculator (excel)

It's a great way to plug in some numbers and get an idea of how placement affects different variables. Don't get too caught up with trying to get it perfect...but it's a good planning and learning tool.

What kind of terrain are you looking to run with this? How much lift height are you planning for, and how much travel (up/down)? Are you willing to hack into the floor at all or do you want to keep it all under the vehicle?

At minimum, you'll need to reinforce the frame rails. The two ways most people approach this are either 3x3 angle or 4x6 box tube cut in half...there is plenty of information on this topic on this site alone if you search around a bit. On mine I ended up using 3x3 angle and ran it basically from the old stock LCA mounts on the frame, all the way back to where the rear coils now sit...however I've got pretty much no stock running gear left, short of the motor...



The rear coils I ended up with are stock ZJ rears. I would estimate the total lift at around 8"....it's nice and level, and the front has new Rusty's 4.5" springs, a 1.5" coil spacer, and the spring mounts are elevated maybe 2" from the axle tube.









The lower links are 2" OD x 1/4" DOM, with Johnny Joints at both ends. Uppers are 1.5" OD x 1/4" DOM with 3/4" heims at both ends. I've been driving it around for the last two weeks or so, and so far I'm quite happy with it.

Best advice IMO, is to go and lay under the rig for a long time and just stare at it. Figure out what compromises you're willing to make as far as link placement. Then grab a measuring device, jot some notes down, play around with that calculator a little bit to get an idea of how things go together, and post the chart/numbers up.

How much do you plan on cutting uo the rear of the rig? You say you're going to run coilovers, have you figured out how/where you're going to mount them?

A couple of general rules to go by:
Get the links as flat as possible, and get them reasonably long.....as long as you can get and still have good ground clearance on the lower mounts. If you will use throttle while wheeling, get the instant center of the rear upper and lower links forward of the top of the front tires, which will minimize the rear bouncing when spinning on an obstacle. If you will mostly crawl and want the rear to stick real good, then get the instant center behind the top of the front tires. The instant center is the point at which lines drawn extending the lower arms and upper arms intersect.

You can start measuring and writing down a bunch of measurements, use some graph paper and plot out various configurations, and/or make good use of the four link calculator. Play around with various mounting positions on the axle as well as on the frame.

Have fun,

i play with lego. Before you laugh though, it is very helpful in learning about mounting points and what they do, where they can be moved etc. in relation to how you want your axle to act.

thank you all for the responces and i will chop up the back where the rear windows are the back seat will be gone and i dont care to cut into the back to mount coil-overs that was kinda of my plan gives the ability to run a longer coil-over and can make my own mounting point. once it gets warmer out i ill deff be getting under it to do some measures i just dont wanna get out there and have a durr face on at least know places to measure from. i have an idea of what i want i dont want a traction bar its only trail rig so im not sure if I need one. also i have 38's that will be going on it with 8-9" of lift. ty for the responses will be checking back every now and then got alot of reading to do along with the help from u guys.

vetteboy said:

You may enjoy playing with this.

Four Link Calculator (excel)

It's a great way to plug in some numbers and get an idea of how placement affects different variables. Don't get too caught up with trying to get it perfect...but it's a good planning and learning tool.

Click to expand...

I'll admit that I have no Idea myself how to build a rear 4 link but would love to learn a bit about it. My rear sucks compared to my front. How about a little insight or tutorial on how to work this program.

http://www.4wheeloffroad.com/techarticles/suspension/131_0307_four_link_suspension_part_2/index.html
i did my first using this...probably a bit more time consuming than a program but it worked pretty well.