3link wishbone or single Triangulated 4link rear? ideas, pics.

[ashmanjeepxj]

ashmanjeepxj,
I am using a wishbone 3-link on the rear of mine, C-roc supplied me with the design for it and it works awesome, I would pm him and pick his brain about them. He has been using it for a long time now and has not had any problems, I only had one thing go wrong with mine and that is only because I did not get a good enough weld but 3 Batteries and some rods at the trail fixed that.

Im doing the Hydro assist this weekend. Just need the 1/4in npt to -6AN fittings, should be able to get that tomarrow morning from the hotrod shop.

Ill show you guys pics when I get around to starting the rear.. Havent bought joint yet...

 

[BrettM]

be sure to post some pics of that hydro assist also! i think I'm going to get the same cylinder.

have you checked out the Jimmy Joints from PolyPerformance(.com)? They're pretty similar to an 1.25" heim, but rebuildable and I think more misallignment, and supposedly cheaper once you factor in the spacers and stuff you need for the heim. they're in the vendor's section on PBB.

 

[Matt]

I doubt that this thing will break. The links are 1.5" DOM 0.120" wall and the uppers are welded as one piece with the heim joint. The heims are rated 40.000 lbs and the bolts are all 12.9 strength which equals grade 8.

I would really urge you to A: mount that joint in double shear and B: increase the size (EDIT: if they are 1" bore you should be OK there)

I have personally broken heim joint in the front end of my triangulated 3 link and trust me the heim failure is not big problem - the collatoral damage is. The carnage was massive and it is a pain in the butt to get the axle rotated 90 degrees back to its original location on the trail - rig a fix and deal with the driveline carnage, brake line failure, bent links and other damaged items (it will likely fubar your t-case if your are really talented)

It would take you a couple of hours; spend the time to box in that bolt atop the diff- also my preferance is to position the heims so there are at zero misalignment at static height - limits possible binding

I ended up going to a bushing to solve my issues and with an inner sleeve and an outer collar the set up has lived happily for close to 18 months now... I eats the bushing from time to time but you do not have total failure like a heim...

I also run a clevis back up in case it really goes bad the axle cannot flop around much:

Matt

 

[XJoachim]

Thanks Matt, the clevis is a great idea, will fab something similar that catches the axle in case something breaks. Right, they are 1" bore heims with 1" tread.

I also fabbed a center limiting strap that will also catch the axle in case of breakage. I know it will not hold up to drive out of an obstacle but it will minimize damage. The top bolt will be boxed to double sheer.

Thanks for all your suggestions. :wave:

 

[chassellbandit]

I've only got crappy shots of my double tri 4 link during build. May have some more after this weekend though.

This was where I thought it would be, but I ended up dropping the body 1" lower which made the lowers almost dead level.

It doesn't matter to me whether you have a 3 or 4 link, just make sure you can have some adjustment so that you can actually play with it without having to hack apart the whole thing.

I wouldn't be too worried about a 1" bore heim no matter what way you have the bolt axis facing. I have this one on my front 3 link and the bolt axis is parallel to the ground. I don't see it ever having a problem. That's a 5/8-3/4 next to it for comparison.

bear with me, just tryin to learn. y are the upper links mounted so high over the pumpkin? could they be dropped down lower, allowing the frame end to be dropped lower as well? i.e. not hack the body that much. looks like a hella beefy setup, nice job.

 

[JeepFreak21]

bear with me, just tryin to learn. y are the upper links mounted so high over the pumpkin? could they be dropped down lower, allowing the frame end to be dropped lower as well? i.e. not hack the body that much. looks like a hella beefy setup, nice job.

Because he cares more about the ground clearance then the preservation of the body.
Billy

 

[chassellbandit]

so solely a clearance issue. ok, makes sense to me. thanx

 

[JeepFreak21]

so solely a clearance issue. ok, makes sense to me. thanx

Not to mention other issues with the complex geometry of a link suspension like that.
Billy

 

[ashmanjeepxj]

Not to mention other issues with the complex geometry of a link suspension like that.
Billy

Since his lower arms are mounted above the axle tubes (for clearance) the upper arms have to be moved higher so there is enough seperation. Teh upper links and lower links can not be very close together or they will over stress the joints.

Also moving the upper links to a high mounting location keeps the link flat (less angle) that is good.

 

[4ward]

Ground clearance is just an added bonus of the james link, or whatever they're calling it now. I wanted a high roll axis to keep body roll down and needed to keep the antisquat #'s below 100%. Plus I like to build new(to me) things and now I've had a hand in 4 of them.

 

[ashmanjeepxj]

I have a godo start on my 4link project...
http://www.pirate4x4.com/forum/showthread.php?p=3142976&posted=1#post3142976

Lower link axle end

 

[ashmanjeepxj]

Frame end mounts

Upper link axle end mount...

 

[bj-666]

i know this is prob a stupid question but why dosent anyone use radius arms. bad example but like claytons arms without the link to the upper mound i'm pretty sure you could weld a super beefy peice of square stock or dom to the axle and then have 3 heims at the front desired mounting position. feel free to shoot me down on this one but just curious.

 

[Dirk Pitt]

i know this is prob a stupid question but why dosent anyone use radius arms. bad example but like claytons arms without the link to the upper mound i'm pretty sure you could weld a super beefy peice of square stock or dom to the axle and then have 3 heims at the front desired mounting position. feel free to shoot me down on this one but just curious.

The trac bar is required with a set of radius arms. A triangulated 3 or 4 link eliminates it. This is just one reason.

Lookin good Ash.

 

[JeepFreak21]

The trac bar is required with a set of radius arms. A triangulated 3 or 4 link eliminates it. This is just one reason.

Lookin good Ash.

Another is a radius arm rear makes for a lot of rear stear upon articulation and because antisquat is a much bigger concern than antidrive.
Billy

PS - Looks great Ash! Keep us posted!

 

[JJacobs]

have you checked out the Jimmy Joints from PolyPerformance(.com)? They're pretty similar to an 1.25" heim, but rebuildable and I think more misallignment, and supposedly cheaper once you factor in the spacers and stuff you need for the heim. they're in the vendor's section on PBB.

I've seen those. They look really beefy. Unfortunately, the one I saw was broken right down the middle of the outer cage. It was on Becca Webster's Red Bull RockHer when she tumbled down my course at the last Farmington UROC.

This and similar competition-level breakages, combined with the performance of the track-bar equipped moon buggies, lead me to think maybe we're asking the triangulated or even double triangulated four links to take a lot of load at the heim. Whereas a panhard suspension will do every bit as good a job in overall performance yet school the triangulated 4-links in strength.

I'm thinking my next rig (soon) will have a one-link, or A-frame, or whatever you want to call it rear suspension with panhard. The front will also have a track bar- of course with an XJ that's hard to get away from in the front

 

[THE_OWL]

According to Poly, Jimmys are on back order.

 

[ashmanjeepxj]

i know this is prob a stupid question but why dosent anyone use radius arms. bad example but like claytons arms without the link to the upper mound i'm pretty sure you could weld a super beefy peice of square stock or dom to the axle and then have 3 heims at the front desired mounting position. feel free to shoot me down on this one but just curious.

I would put a radius arm rear suspension at the bottom of My choice list for my type of wheelin:
Double triangluated 4link
single triangulated 4link (could be upper or lower triangulated)
3link wishbone (could be upper or lower triangulated)
5link (4 parellel links with a track bar)
Wristed Radius arms 3 link
Radius arms. 3link

If I was building a mud truck for flat gound and didnt need alot of ground clearance, a flat linked radius setup on the rear would probibly be ideal...
But I need to do steep hill climbs (less swuat), lots of clearance, flex, side hilling stability (High roll axis) that a radius armed rear links cant do.