Traction bars?

Ricky B

Wiiide Open
Joined
Mar 20, 2005
Location
LKN - Tha Dirty Mo (Mooresville, NC)
Ok so I've got two fairly reliable sources telling me that its ok/not ok, to run traction bars instead of a ladder bar, obviously the arguement is limiting of your flex?

I'm talking like a ladder bar that mount above and below of the axle and has a shackle at the frame vs the two single bars that you mount to the lower end of the axle that mount in the frame like the two bottom suspension links of a triangulated 4 link.

Also what thickness of tube should I go with? .25 wall? Bear in mind I have ROCKdubs (6.72 gears), big azz tires, and when I finish rebuilding my caddy 500 cubic inch motor with the performance parts I have I will be near the 400 hp - 650 ft lbs of torque range . . .

thanks
 
this is what im talking about


awww.timskelton.com_lightning_race_prep_suspension_images_lift_bars_v_traction_bars.jpg
 
what you have labeled as a lift bar in the diagram I have always called a traction bar. Nomatter what you call it, the second picture is the one you want to go with. The first picture doesn't have anything to stop the axle from rotating like the second one does.

You mentioned it in your first post but didn't show it in the diagram but make sure you put a shackle at the frame end.

.25" wall tube will work fine.
 
Yea, the ladder bar with the shackle is def what I would do if I go that route, i got a bunch of susp joints and tractor links laying around I could slap together pretty easily (thanks for the offer Jeff)

I was just more wondering about the traction bars because I see alot of people using them in high torque applications (one guy was using them on a ford powerstroke grudge pull truck with 8" blocks successfully, another on a 350 powered one toned trail jeep on 44's) but then other people swear against them, was wondering if anybody had any first hand experience with the single bars, because it would be alot easier to make/mount than the shackle traction bar, and design wise I dont see how it would limit flex . . . .
 
yea i mean that is jsut like the ladder bar and shackle design, not saying that it doesnt work, i know it does, I'm just asking for feedback on traction bars, not ladder bars, I know some guys run them, like I said there literally the two bottom links to a triangulated 4 link and supposidly they stop the wrap . . . . I'm just hopin to get some feedback from someone else who's tried to flex with em cause If they can hold up to that one dudes grudge pull powerstroke on 8" blocks then they aught to be able to handle my junk, I'm just windering how it will affect flex mostly, i mean if you think about it as the leaves/shackle drop if you have traction bars they have the correct geometry to drop in unison and not create bind . . . . I saw a diagram once, if i can find it again ill post it.
 
this is what I'm wanting to do:
http://www.4x4wire.com/jeep/tech/susp/axlewrap/

------------------------------------
awww.4x4wire.com_jeep_tech_susp_axlewrap_soa12s.gif



Single bar systems located below the springs

Single bars located below the springs actually help solve the axle wrap problem somewhat. Most rock crawlers avoid these setups because they don't want to reduce ground clearance, but they are fairly popular with mud boggers. These bars work by by putting the forward half of the spring under tension when axle wrap tries to occur. This tension fights the springs natural tendency to get shorter and turn into an "S" shape by pushing the axle housing back and pulling the springs straight. These bars are still not totally effective for axle wrap control because they depend on the spring to be rigid for triangulation, but they are more effective than bars located above the spring because they tend to straighten the spring when axle wrap occurs making the spring seem stiffer an generally reducing wrap by preventing the spring from going into an "S" shape.

These bars get more effective as the bottom mount for the bar gets lower, but they also lose more ground clearance as the bottom mount gets lower. These bars also somewhat limit articulation because the bar and the spring will swing through different arcs and bind. I'm happy to report that I've never seen anyone selling a setup like this with a swinging shackle at the front end of the bar, because that would make the system useless by allowing the length of the bar to change and preventing the bar from putting tension on the spring.
 
this is what im talking about


awww.timskelton.com_lightning_race_prep_suspension_images_lift_bars_v_traction_bars.jpg

Dunno what this is from, but its all wrong! The top picture only works if there is a top link. Then you trangulate the two links to find the instant center and that is where the system lifts the vehicle! It doesnt just push "forward" any more than the ladder bar does!

That other "shackle link" deal dosent look like it would do much to stop spring wrap, altho it would limit axle wrap. And it would act as a 5th link traction device.

What are ya tryin to accomplish?

In order for the type of traction device, (shown in your small color picture), to work effectively, wont it do away with all yer flex? And if it is rigid mounted on both ends it will create a hell of a bind as the spring and the bar try to rotate about different centers!

BTW, any solid device that will increase "forward traction" under acceleration, will also "unload" the chassis on decel. Makes comin down a hill pretty hairy! Thats why leaf dirt cars always used 5-6th coil-overs or "reese bars". They would run the antisquat up to 104-110% under accel, but then would allow the antisquat to return to 100% or less under decel.
 
(lift bar) most control over axle, least flex
(traction bar) middleground
(shackle style) most flex, least control of axle
 
What are ya tryin to accomplish?

In order for the type of traction device, (shown in your small color picture), to work effectively, wont it do away with all yer flex? And if it is rigid mounted on both ends it will create a hell of a bind as the spring and the bar try to rotate about different centers!

I mean just tryin to keep my rocks from yankin themselfs out, I have yet to be able to just romp on it because they wrap so violently

I mean that was why my front drive shaft kept pulling out, I could flex her all the way out on the ramp and still have like 1.5" travel left in the slip but just sitting still if i popped the gas fast the front axle wrapped so much it pulled out the driveshaft every time . . .

if the single links have joints that can pivot on either end then how would that bind up the suspension?
 
FWIW, ricky, i think scott waters is running that single link design on his CJ...

with that or the ladder bar with a shackle on the frame end, the closer to the center of the axle you can get them, the less theyll limit flex...
 
yea i forgot he was runnin em, i mean i see a good bit of people doin it, I guess I'll just try it and see what happens :driver:

on a side note the agri supply up here has tractor links in almost every size and length, if I find some that are all ready the proper length should I sleeve them still with some thicker tube or just run em as is?
 
Ever looked at the late model Land Cruisers? I think they are the FJ80's. Take a look at the Front Lower Control Arms. Very similar to a Ford Radius Arm, but instead of a stud on the Frame mount end, it has a Eye with a bushing. Find one from a Scrap yard, and mount it over the axle. Seeing as you're running rocks, you may need to get creative on the axle bracket though.
 
...

if the single links have joints that can pivot on either end then how would that bind up the suspension?

If both points are fixed, even though they pivot, the axle will try to travel two different arcs. See the issue?
 

Attachments

  • Image1.jpg
    Image1.jpg
    13.3 KB · Views: 466
my anti-wrap bar eliminated all of my axle wrap, even with these super soft xj leaf packs...

the shackle needs to be perpendicular to the traction bar to avoild having the suspension flex (raise one side, lower the other) when you romp on it....

start:

ai47.photobucket.com_albums_f175_efrancin_CIMG0951Medium.jpg


ai47.photobucket.com_albums_f175_efrancin_CIMG0955Medium.jpg


finish:

ai47.photobucket.com_albums_f175_efrancin_CIMG1032Medium.jpg


ai47.photobucket.com_albums_f175_efrancin_CIMG1028Medium.jpg



ideally, it should be on the driver's side... this wasn't an option for me b/c i was too lazy to redo my exhaust... it still does the job on the passenger side, just causes more suspension flexing when i romp it on out of the hole...
 
Hey Eric did I sell you those axles? I sold em to some dude from the beach that also got xj springs from me I just can't remember who it was . . . :lol:

anyway yea I mean the ladder bars def work

oljeeps - thanks for the diagram that makes sense, my next problem is gonna be figurin out how to mount anything to the front axle, my steering pretty much blocks all rear access to the axle . . . . :confused:


anybody want to let me borrow some random coils and some upper and lower FSford buckets? Might as well just 4 link it and not worry bout it . . . :lol:
 
nah i bought them from danny @ CF4x4 a little over 2 years ago... he got them from up north somewhere....

i'm always looking for more XJ springs though :) You could stockpile a bunch and give them to me so that everytime you see me at uwharrie you can tell your friends "I'll be right back, I gave that douche those springs and I need a beer!"

:)

-Erik <---- hasn't seen any signs of my flex being limited with that bar, though i don't understand how
 
Another Question . . . . Whats a good length to make the bars? I'm doing the ladder bar stlye and putting them both on the driver side so technicly if I wanted to I could take both to the center of the Jeep almost touching each other If I wanted to . . . .

But I'm thinking longer might not be better . . . wouldn't it cause more leverage for the axle to twist the frame mount off with? Or more Prone to bending the bar. But then again wouldn't longer flex better?
 
why do you need to flex in the mud?
 
are you going to be able to use the frame mount i dropped off for you? it was used like Erik's pics here. (but on drivers side)
 
are you going to be able to use the frame mount i dropped off for you? it was used like Erik's pics here. (but on drivers side)

Yea it should work, just gotta figure out where I want to mount it at


why do you need to flex in the mud?

Good point, while my rig is more mud oriented I still want to be able to do all around kinda wheeling, so to an extent I need some flex . . . If it was strait mud the thing would be sky high to get the body and whatnot up outta the mud :driver:



Anyone have any ideas on the length I should make them?
 
Back
Top