So i've been doing a lot of check-ups and a few changes here and there and figured i'd throw the plan on here and get some opinions.

My MJ is setup with long arms, a y-link setup to the front axle..

Pic:


Now the bushings at the axle end of the long arm are pretty wasted out. Rather than just replacing them, would i be better off to just swap out the bushings for a 2nd pair of johny joints?

pic:


I have already made plans to change my upper radius arms to a double heim joint rather than a heim joint to bushing. i know the bushing on the top of the radius arm restricts and suspensions flex as it binds the axle more than it lets it twist with the suspension.

Just figured it could only help with the suspensions flex to have all flex joints.

Only immediate downfall i see is the suspension may clunk more being all solid joints rather than some give with the bushings. Please fill me in otherwise.

I do drive my truck on the road often so drive ability is a factor for me.

 

you have it backwards. you need the bushings there to allow a y link to flex.

there is an inherint binding with radius arms(y link) and as you flex, something needs to deflect. The bushings take care of that deflection. If you put solid joints in there, whats left to flex are the control arm mounts, and they will do so by cracking to pieces.

 

so i should just leave the bushings on the long arms then

 

because some people find the binding hard to understand sometimes (not saying you don't get it, just putting this here for others who come across this thread). Allow me to explain it this way:

take 2 plastic forks and cut out the 2 inside prongs.

pretend these are your 2 "y link" control arm setups. the top prongs mount to your uca mounts, and bottom prongs to your lower control arm mounts.

Put them both horizontally on a piece of paper.

now without moving the very end of the handle, pivot one of the forks down as if you were flexing.

draw a line between the 2 prongs on each fork.

See the degree difference? Something has to make up for that. And you sure don't want it to be your axle tubes or control arm mounts. This is why Y link setups use bushings at the axle end.

 

so my raduis arms should stay heim-bushing as well then..

to be honest the whole plastic fork "metaphor" has me confused. I really learn better hands on over reading.... gonna have to youtube and google info y-link setup and better educate myself i guess.

 

here is a crude picture.

You are viewing your jeep from the side while flexing,the black arms are compressed and the red arms are drooped. the grey lines are just there to show the angle between the control arm mounts.

see the angle difference between the uca and lca mounting points on the axle?

 

Now it all makes sense, thanks for the pic. I think I just might convert my radius arms to a true four link. Has anyone ever done it?

 

Built a long arm 4 link?

Oh yeah.

 

Can the uppers from the y link, be lengthened to connect to the frame? I'm still aliitle lost as to why anyone would want a Y link when you just as easily build a four link. Any ideas?

 

Non triangulated four links (xj front long arms) still bind

 

3 link...

 

i chose a y-link because my close friend had already set his XJ up for it and it flexed amazingly well. Also it wasn't all that difficult to setup.

On another note, i pulled my long arms off today and the bushings on the axle side of the long arms were whooped out.. the bushing sleeve actually just fell out of the bushing itself.. maybe i can add pics later... But i've decided to go with an extra set of Johny joints instead of just replacing the bushings (they're actually factory lower control arm bushings in a machined sleeve *Rustys Offroad*). So its gonna be a johny joint at the frame mount and at the axle mount. After greasing them shouldn't have to touch em again for a while.

 

That is a great explanation KTM!

 

thought i would provide some pictures for this interested in a radius arm setup










bushing sleeve just fell out

 

Would there be less binding with radius arm if you had one long arm and one radius arm. I like tnts Kit mostly because way arms mount to crossmember and arms are bent to keep tire off arm at full lock but want good droop, with little binding. Could I run without one of radious arm if axle mount was reinforced?