3 link and 4 link ideas

[Dr. Jeckel]

I designed a wishbone 3-link and double triangulated 4 link for my xj cherokee using autocad(intial design) and Inventor software to model it. My cherokee has a 6" lift and 33" tires. We have a 3D modeler where I work so I made a model of the 3 link just to kind of test out my idea. It was before I made a couple tweaks to the design.

I read ALOT(until my head hurt...took a break and read some), looked at a bunch of pictures of linked suspensions and think I KIND OF understand the basics involved with using the calculator and what the various items mean and affect.

I decided to just keep my leaf springs for the time being and just do a truss with an anti-wrap bar, which I'll post some actual pics up later once I finish it, but wanted to put up the pictures of the link designs and the calculator numbers for those that might be interested in doing something similar.

The crossmember mounts to the underside of the unibody and the upper link mounts are designed to sit about 1/2" below the floor. This will require the floor to be clearenced progressively to about 2-3" near the center of the upper links for up travel.

Anyway, I know it's not an actual build but I know that I like looking at pictures for ideas and thought that it might give someone else ideas.

Here are the pics for the 3 link:
Lowers would be 2" square tube .25 wall thickness with 7/8" heims and bushings. Uppers would be 1-1/2" .120 wall sleeved with 1.25" .120 wall that merg into a 2" square tube .25 wall thickness and use a 1.25" heim and bushings.

Here are the pics for the 4 link:
Lowers would be 2" square tube .25 wall thickness with 7/8" heims and bushings. Uppers would be 1-1/2" .120 wall sleeved with 1.25" .120 wall with 7/8" heims as well.

Maybe some day I'll actually put one of these ideas into practice, but until then I hope it helps someone else out when thinking of ideas.

James

 

[MoparManiac]

How are you going to get the inside of the square tubing smooth in order to sleeve it?

There's a welded seam inside of it.

 

[babyhuey]

I like the design, that's what i have planned for mine. Why are you planning on sleeving the uppers, wouldn't .25 wall square be strong enough on its own and just use square tube inserts for the joints?

 

[Dr. Jeckel]

How are you going to get the inside of the square tubing smooth in order to sleeve it?

There's a welded seam inside of it.

I would clearence the outside on the 1.25" tube...creating a shallow groove to match the weld seem on the inside of 1.5" tube.

 

[MoparManiac]

That, to me, just sounds like a PITA with either the 3 or 4 link.

I would just use DOM for the upper, or at least ONE size for the uppers.

I don't get what you're gaining by sleeving.

 

[Dr. Jeckel]

I like the design, that's what i have planned for mine. Why are you planning on sleeving the uppers, wouldn't .25 wall square be strong enough on its own and just use square tube inserts for the joints?

They don't sell 1.5" .25 wall square tube at the place I usually buy from, according to their materials sheet. I would rather use .25 wall and probably if I were to check around could find some.

The only other factor is that with using a 7/8" heim, and having a 1" I.D. for the 1.5" .25 wall tube wouldn't work.

 

[Dr. Jeckel]

That, to me, just sounds like a PITA with either the 3 or 4 link.

I would just use DOM for the upper, or at least ONE size for the uppers.

I don't get what you're gaining by sleeving.

It would honestly take about 5 minutes per side to clearance. I have a circular saw with a metal cutting blade and would just set it to about 1/32" depth and run it the length of the tube.

What I'm gaining would be additional strength. 1.5" .120 wall just doesn't seem beefy enough to me...although the way I drive, would probably last forever. I could just go with 2" uppers but that would mean additional clearancing of the floor and the 1.5" tube also give me a little more room between the links when flexing the suspension.

The 1.25" heim requires a 1.5" I.D. for the tube insert, that is why they merge into the 2" pipe and also for additional lateral strength.

 

[MoparManiac]

If you're worried about clearance then get some round tubing.

1.75 x .120 wall is a very common UCA size.

 

[Vanimal]

i have a very similar setup that i will be transplanting from a zj to my xj as your first model. the only difference is my lower control arms go straight out and mount to the bottom of the frame rail. i'll be welding in some coil buckets.

 

[dart70LA]

That looks great, but the differential is not offset to the driverside like it is in an XJ. Won't you have trouble with the Oil Pan and the driveshaft?

 

[VAhasnoWAVES]

i believe they are both meant to be rear applications...

 

[dart70LA]

i believe they are both meant to be rear applications...

:speepin:
I'll drink some coffee before I post next time.

I saw where he decided to stay with leaves, so made the assumption(wrongly) that he was designing the system for the front.

Now I can whole heartedly state, that the systems looks great.

 

[Goatman]

Fun project, I'm sure, and a great way to learn. I don't get why you'd use square tubing, no benefit and round is easier to work with. The uppers don't need to be that stout, but it doesn't hurt anything other than adding extra weight. My rock buggy has 3 links front and rear (not a wishbone, actual 3 links) and both front and rear arms are .120 wall. It's been through 3 King of the Hammers.

The wishbone or the 4 link will work exactly the same, and technically the wishbone is still a triangulated 4 link. The choice between the two would be purely ease of building, no performance benefit of one over the other.

Something to do at work?

 

[Dr. Jeckel]

I have no preference of square over DOM....it was mainly due to the fact that I've only used square tubing on projects and the cost difference compared to DOM.

 

[DeftwillP]

Do you need a guiniea pig in the red river chapter?