y links vs upper and lower controll arms

W

Wolfie

NAXJA Forum User
Location
Colorado
a friend of mine was telling me that they have kits with Y links instead of an upper controll arm, whats the pros and cons of this set up, and is it good or bad for hardcore articulation?:confused:
 
TNT (now Treks offroad) makes the Y-link radius arm kit. The pro's are you have increased ground clearance, and you have great flex since they are long arms. I know a ton of people on here love them.

The only person I know with them is Colin (MoparManiac) and he has pretty crazy flex, but is replacing bushings almost daily. Radius arms bind when you start to get flexy with them. The upper arms are now attached to the lowers, rather than the frame, so the axle doesn't follow the same path as it did before. This is inherent with radius arm set ups.
 
Re: y links vs upper and lower control arms

biggest drawback is unloading during climbing, they flex like mad
 
Everything flexes like mad. In the range of travel that works well every control arm/suspension type will provide enough flex. The Y link is basically a radius arm setup, the upper arm is attached to the lower so they move together with the axle. This means that as the axle articulates the arms are trying to twist the axle, so the deflection must be taken up in the bushings. Picture the arm on one side pointing slightly down and the arm on the other side pointing slightly up. This can wear out the small stock upper control arm bushings, how often depends on how often the rig is wheeled or how hard it's wheeled. The TNT Y link is a pretty good design, very good ground clearance, the best for any long arm kit.

A non-radius arm design, where the upper and lower links attach to the frame, doesn't have that bind as the upper and lower links move independantly of each other. In a long arm kit, Full Traction does it this way, but their kit doesn't have the good ground clearance that the TNT kit does. Either design works well, you won't know the difference on the trail from the control arm configuration but you'll know the difference from the ground clearance, and you'll replace upper bushings more often with the Y links.

You said "for hardcore articulation". For hardcore trail running, ground clearance is more important.
 
flex is great as it allows more tires to keep contact with the ground thus better traction...
but if your locked, does there become a point of TOO much articulation?
which is worse...getting a tire in the air periodically or keeping all tires on the ground but the jeep is CRAZY flexed out?....
 
Goatman said:
Either design works well, you won't know the difference on the trail from the control arm configuration but you'll know the difference from the ground clearance, and you'll replace upper bushings more often with the Y links.
Click to expand...

Well...it's always fun watching front axles do the 'radius arm boogie' on hill climbs. Just about any radius configuration I've seen will do that given the right traction conditions, while a 3-link does a much better job of avoiding this. Disregarding things like suckdown winches - I'm talking about 'average' trail rigs.

in4aride said:
which is worse...getting a tire in the air periodically or keeping all tires on the ground but the jeep is CRAZY flexed out?....
Click to expand...

I'm reasonably convinced the answer to this question is "yes". :D Both have their benefits and drawbacks. I think the key is to 'comfortably' limit your articulation based on your components - shocks, u-joints, steering, etc. I have 12" shocks mounted vertically on each corner, and I basically use all the travel they give me...I don't think more travel would be beneficial, and I get pretty close to binding the front t-case u-joint at full droop anyway, so I wouldn't want any more as it is. Meanwhile I've never been in a situation where I feel like less travel would have been helpful.
 
ive noticed some jeeps get the weight transfer a lot sooner(if at all) with shorter amrs/less articulation....
is the weight transfer a good thing or is that situational?!
(this is frst real jeep build and im new to the wheelin stuff so bare with me)
 
well thats the "situational" aspect...
lets say droppin into a trail like independance in CO...
there are HUGE drops....jeeps with a lot of flex keeeeeeep on flexin and then the weight of the jeep just plops down all at once...seems kinda bouncy and stressfull on the rest of jeep(driveline/body)
short arms dont flex as much so weight of jeep moves gradually with the jeep as it drops down...


at least thats how it appears to work to me...

basically...
long arms seem like they dont evenly place weight(thus traction?) to both wheels...whereas the shorter arms seems to keep things more level and less bound up????
 
vetteboy said:
Well...it's always fun watching front axles do the 'radius arm boogie' on hill climbs. Just about any radius configuration I've seen will do that given the right traction conditions, while a 3-link does a much better job of avoiding this. Disregarding things like suckdown winches - I'm talking about 'average' trail rigs.
Click to expand...


Does the "average" trail rig have a 3 link?

:D
 
Goatman said:
Does the "average" trail rig have a 3 link?

:D
Click to expand...

:gag:

in4aride said:
well thats the "situational" aspect...
lets say droppin into a trail like independance in CO...
Click to expand...

I know the spot you're talking about.

The thing about flex, is that in extreme cases it becomes a delicate balance of physics. Weight distribution, center of gravity, spring rate, roll center, all that stuff comes into play when trying to decide how well a certain rig will do in a certain spot.

So yeah, you could 'design' a suspension - including all those things I just mentioned - that would be awesome at the Indy entrance. Would it be equally awesome at everything else? It's tough to say, but I doubt it. At this point in my wheeling experience, I prefer moderately stiff springs, which inhibit the real slinky kinda flex, but feel MUCH better at speed and much more stable overall.

The only way you're going to know what works for you, your vehicle, and your terrain is to get out wheeling. No one gets it right on the first shot. I *thought* I liked the front springs I ran for a year and half until I swapped them out for stiffer springs and air bumps, and it's like driving a totally different truck now. I know for a fact my rear springs are too soft and I've been slowly working towards changing them for something stiffer as well.

But, I've also been moving towards a 'faster' pace of wheeling, and where soft springs and big articulation may have worked before, it's not ideal anymore. Only seat time and trial/error can fix that.

One thing I will say is that short arms and compromised geometry is NEVER a better solution. If the basic geometry of your suspension is the limiting factor you'll never be able to tune it the way you want.
 
vetteboy said:
One thing I will say is that short arms and compromised geometry is NEVER a better solution. If the basic geometry of your suspension is the limiting factor you'll never be able to tune it the way you want.
Click to expand...

please define 'short' as used above.

My lowers are about 20.75" long and my upper is about 23.5" long...

and I dont think that my geometry is 'compromised'...
 
XJ_ranger said:
please define 'short' as used above.

My lowers are about 20.75" long and my upper is about 23.5" long...

and I dont think that my geometry is 'compromised'...
Click to expand...

The way he was using it made me think "stock" or "stock-ish", as opposed to something that addresses the issues you have when lifting something.

Basically something that results in the second sentence you quoted.
 
XJ_ranger said:
please define 'short' as used above.

My lowers are about 20.75" long and my upper is about 23.5" long...

and I dont think that my geometry is 'compromised'...
Click to expand...

where did you mount them? stock location, just with axle pushed forward? i'm intrigued.

so i've learned a lot between reading this thread and finally reading the entirety of colin's thread. i decided i have a question, in light of what i read. somewhere, i do not remember who, but someone mentioned that the bushings compress front to back on the vehicle even on stock style setup. that makes perfect sense to me with respect to the information presented. now, my question is why do some companies sell factory style suspension arms with flex joints at both ends? i'm especially curious, because i am currently running a set of RK short arms with flex joints all around. the only poly/rubber bushings in my front suspension is the lower track bar (not that the track bar makes a difference for this... it will be getting a hard joint at the lower end soon, anyway) and the UCA axle side bushings. (i just put WJ bushings in last weekend, actuallly). the seem to ride well and flex fine... so i don't understand how it seemingly works well but isn't really a great setup. thanks in advance.
 
You must log in or register to reply here.

Similar threads

B
Long Arm kits, Pros, Cons, good the bad???
Replies
13
Views
450
Ghost
Ghost
B
Long Arm
Replies
2
Views
245
maxbraketorque
M
N
  • Locked
Lowering An XJ
Replies
0
Views
395
NAXJA_Archives
N
Jeepedo129
XJ Build, again.
2 3
Replies
55
Views
3K
Evan03
E
M
New to my XJ & wrenching - How to choose parts and what to prioritize?!
2
Replies
31
Views
5K
Anak
Anak
Back
Top