Traction bars

[Jason M]

There has been a lot of talk lately about how to properly build a traction bar. The one thing that I cannot figure out in my head is why is it better to have the shackle at the frame end go upwards instead of downwards (like Woody's)
Mabye it is my limited imagination but I cannot figure out why it would make a difference other than for clearance issues..

Just wondering if I should try to redesign mine.

[COMPLAINE]

I have made 2 that go up instead of down, and it makes no difference.
And just as something to think about; on the most recent one that i made for a friend i made the shackle pivot in the middle so that it has no limitations for suspention movement, and so that it doesn't over work the bushings and rod ends. Also make all of it stronger than you think it needs to be, they take waaayyy more stess than you can think. And you will be happy when it never breaks.

hope that helps. Good luck.

Ian-

[DCruiser138]

ian can i see some pics of yours? i never took a good look at it on the trail..i never thought id need one so soon! thanks dude..also...was it hard? what did you se and how much will it be out the door?

[70Cruzer]

I think its because of the way the pinion rotates under load (upward), but its shouldnt be a problem mounted either way. FC187 made mine (awesome job btw) and it has the shackle on top of the traction bar, while his is incorporated into his skid plate and has the shackle on the bottom.

[Tankota]

I put the traction bar so it attached to the top of the shackle...then it is at the top of it's arc of movement. It (the shackle) really has no where to go.

However...in theory if you attach to the bottom of the shackle, the shackle could possibly want to go up on either of it's arcs of travel.

I don't think it really matters though, cause people are making them both ways with the same results (i.e. no wheelhop).

[Jason M]

I know the wheelhop issue is controled both ways but a couple of people have suggested that there will be binding of the suspension with the bar positioned at the bottom of the shackle...

[peterfj40]

can i make my traction bar mount onto a shackle that is moounted to my skid plate? it's a stock style skid plate w/ 6 bolts holding it onto the frame..is it strong enough? i'm asking because i had to cut out the original x-member...or should i make a new x-member and mount it to that??

[EricFJ40]

Make a new cross member to mount it to. I think the stock skid plate would probably bend if you mounted the bar to it. I have bent and broken traction bars that I thought should hold up (1/4" wall tube, braces, etc), the moral of the story is "Build it beefier than you think it should ever need to be".

[woody]

Originally posted by Jason M
I know the wheelhop issue is controled both ways but a couple of people have suggested that there will be binding of the suspension with the bar positioned at the bottom of the shackle...

I've heard that comment as well....personally, to get any more flex out of my rear leaf springs, I'd have to disconnect the spring shackles. They twist up excellent. A traction bar like mine is not a perfect solution, but unless you want to spend the time to analyze the suspension movements and love geometry, it's a proven solution....

[wngrog]

Jason
For what it is worth, mine is mounted up to a new crossmember that bolts to the frame.

[fc187]

I personaly think that as long as the shackle is verticle, it dosent make a fricken bit of difference. In one position it is under tension stress and the other way it is uder compresion stress..

This is the designe I use, and it does eliminate axle wrap (rotation) but I dont belive thats where the bulk of the stress comes from. The bar is under the most stress when the weight of the veh suddenly compresses the susp. like when you hop off of a rock or drop off a ledge. Fix the ladder bar onto your axle. remove the shackle, take a peek at where the shackle end of the bar is. now highlift you rig up. that point is now WAY lower. and under comp, it is way higher. Asside from limiting wrap, the bar also has the job of twisting your axle, fighting your springs as the compress and extend. No big through extension (weight of the axle) but sudden compresion, ouch. That bar is now instantly twisting that axle downward with the weight of the veh forcing it.

no big deal, verticle travell and gobs of compresion is for baja racers. If the bar is mounted center on the axle like most cruisers allow, the bar will actually move very little during articulation. Just keep in mind when you build your bar that they are under allot of stress. Make sure they are fastened to the axle Very securly. You also need a solid mounting ponit for the shackle hanger. I would avoid mounting it to a stock skid plate. I mouted mine to my skid but it is hay beefy! the plate is 3/8 ht.


Don

[40_Bones]

Here's mine. It uses a heim joint at the front to allow for unrestricted movement. Sorry the pic is kind of fuzzy.

[40_Bones]

Here's the back

[GloNDark]

Hey 40_Bones. That looks killer! I was thinking about trying that out on my cruiser and looks like you had the same idea that I did. How do you like it?? Where did you get that hiem joint out? Is it anything special??

[40_Bones]

Originally posted by GloNDark
Hey 40_Bones. That looks killer! I was thinking about trying that out on my cruiser and looks like you had the same idea that I did. How do you like it?? Where did you get that hiem joint out? Is it anything special??

Haven't had any problems with it yet. But I still have an 6 in it (until next week just ordered my crate motor ) Just make sure
the axel plates are stout. I have a pattern for them and could sell you some if you like. The heim can be had from McMaster Carr for cheap.

[Brandon]

Ditto that, very clean! I like that it is lower on the axle - one of the reasons I don't have one like that (yet) is clearance - did you add a crossmember bar there for the shackle?

fc- what you said about forcing the axle doesn't make sense, isn't that the whole idea with the shackle? My bar forces it but like ya said no dessert racer here. The reason I want to put the shackle design on though is for the up n down travel? You got be a bit confused ???

[Eric]

Brandon.......you have a Cruiser now????

[Brandon]

Originally posted by Eric
Brandon.......you have a Cruiser now????

No but my jeep has a cruiser rear axle

Between my two rigs I got every vehicle made I think lol

[40_Bones]

Originally posted by Eric
Brandon.......you have a Cruiser now????

Brandon,

I assume you're asking me about the cross member. It is mounted to the stock one. I also have the rear springs turned around to add wheelbase. You could just make the track bar shorter though if your wheelbase is stock.

[fc187]

Originally posted by Brandon

fc- what you said about forcing the axle doesn't make sense, isn't that the whole idea with the shackle? My bar forces it but like ya said no dessert racer here. The reason I want to put the shackle design on though is for the up n down travel? You got be a bit confused ???

ok, then try this experiment,
install a ladder bar/shacke traction bar onto your rig. with your veh off (no torque being applied to axle), jack up your rig as high off the ground as you can with the axle extended and hanging free. now here is the cool part. LAY DIRECTLY UNDERNEATH the end of the bar with the shackle. keep you eyes on the the end of the bar,.....real close.......Im talking like an inch or two. Now REMOVE the shackle!

and when you come to,.....you will understand.

the shackle compensates for the forward and aft movementof the axle as it extends and compreses.

remove the shackle and have some drunk buddy bounce up and down on your rig. the distance between the end of the bar and the shackle hanger will change with the bouncing. Now the shackle dosnt stretch, and when it is in place it dosnt prevent you drunk friend from making your rig bounce up and down and up and down.
something has to compensate right?..... during verticle travell (not articulation) the axle rotates on a new axis (the joint at the end of the bar) so now the leaf springs are allowing the axle to twist on that new axis.

Dont get me wrong, I like this designe. I use it , and I have built a few for other people. all I was getting at is that it needs to be BUILT! because its not just under stress from the engines torque.

[Sixgun]

Okay, then why does Decker sports Land Cruiser traction bar work so well? It has a solid mount point with heim joint (no shackle) off the rear cross member. One bar thats bolts into a welded sleeve off of the diff. He claims that no one has ever broken a pinion running his traction bar, but it obviously does not allow the movement of an axle during the compression or extension of leaf springs and therefore inhibits articulation. I guess the point I'm trying to make here is that if a constricting setup that Decker Sports sells will work and (it's not beefy at all) why does a shackle setup has to have a ladder type link with it's own cross member? is there some inherant quality in a shckle type traction bar that warrants extra beefiness, or do we just like welding and adding pounds to our already heavy Cruisers?

[Brandon]

Originally posted by Sixgun
Okay, then why does Decker sports Land Cruiser traction bar work so well? It has a solid mount point with heim joint (no shackle) off the rear cross member. One bar thats bolts into a welded sleeve off of the diff. He claims that no one has ever broken a pinion running his traction bar, but it obviously does not allow the movement of an axle during the compression or extension of leaf springs and therefore inhibits articulation. I guess the point I'm trying to make here is that if a constricting setup that Decker Sports sells will work and (it's not beefy at all) why does a shackle setup has to have a ladder type link with it's own cross member? is there some inherant quality in a shckle type traction bar that warrants extra beefiness, or do we just like welding and adding pounds to our already heavy Cruisers?

wouldn't last in the desert, look in the tech section for my single bar. Has worked for years for me BUT it is designed for articulation not travel - in other words diff stays in the middle it works great, go high speed bumps it probably won't be so happy

[Sixgun]

Brandon, I know of very few people (that have any sense) that use SWB's for high speed bumps. I know my 32 year old vehicle would buck me into my roll cage if I tried any desert racing, I'm looking for arti bro!!!

[Brandon]

well then a single bar works

[Sixgun]

I'll PM ya