Traction bar shackle

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No I am saying it is much better to do the opposite, sorry my post you quoted is unintelligible, my bad. The opposite of of what lucky 13 and sputnik posted, wrap bar at bottom of shackle. The lower the instant center the better, and the longer the bar the better as well. Trust me, it really makes a world of difference to the climbing ability of the truck.

So this design should climb better? I had no idea when I built mine like this, it just seemed easier to me. Sometimes even a blind squirrel...
whitedeer 016.webp
 
Well no, not in that case, they are close to the same. To take advantage of what I am suggesting, you need to lower pivot of the front of the wrap bar: longer shackle, or lower the whole assembly. Bring it down to the skid.
 
So this design should climb better? I had no idea when I built mine like this, it just seemed easier to me. Sometimes even a blind squirrel...


There is not a easy yes/no answer to your question. Because of limitations is design a shackle that is above the bar tends to be better, but if you make the bar shorter and with a high angle to it, you will not climb as well. Yours seems to have a pretty good angle to it.

Long and flat is the " best" solution. However, making that fit and not be a rock finder is commonly tougher than one might think..
 
what would happen if a shackle was not used at the forward end of the traction bar and was attatched or pinned to the skid plate as pictured above with a johnny joint?

would this not work properly?

is the shackle used to lower the moment of the bar and make it closer to the horizontal plane of the rear axle?
 
what would happen if a shackle was not used at the forward end of the traction bar and was attatched or pinned to the skid plate as pictured above with a johnny joint?

would this not work properly?

is the shackle used to lower the moment of the bar and make it closer to the horizontal plane of the rear axle?
Howdy! The shackle allows for the fore and aft movement of the axle. As the leaf springs flex and flatten, the axle does have some travel front to rear. Without the shackle, the mount will have to endure extreme stress. The only broken ones I have seen are ones designed without the shackle and johnny joint setup. John
 
sputnik40, what is that radius arm out of? That looks like a quick and easy traction/anti wrap bar set-up. No need to fab a bar..already done for you. just attach to axle and make up a shackle and your done. I like it.
 
captcory said:
sputnik40, what is that radius arm out of? That looks like a quick and easy traction/anti wrap bar set-up. No need to fab a bar..already done for you. just attach to axle and make up a shackle and your done. I like it.

FJ80. The curvature helps keep it out of the way - and it's actually lower at the shackle point that the way it appears BUT I agree with Bustanutly and other comments by Poser in other threads. My preference was to have the shackle end of the trailing arm in synch with the front spring hanger eyes (i.e. flat) - multiple design needs and a hack rush job put it too high. I have some anti-squat climbing problems in loose and nose to the sky climbing situations - if the terrain is sticky enough (say granite or solid rock or other) then I can stagger my approach to offset some of the squat. But if the climb is loose and steep it really takes some effort to get it up - not that it's not possible, but would be a lot easier I think if I'd gotten that arm in the right spot....

It's a killer on flat knarly rock gardens at least :D.
 
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I agree with the longer the traction bar the better, and lowering the the tube the shackle mounts to is better, however the twisting force applied to the chassis
is the same if you push from the bottom or pull from the top of the shackle mount. Your instant center won't change as a result of which direction the shackle points from its mount. Although I don't really know if you could feel a seat of the pants difference, "shackle up vs shackle down" in a properly set up
wrap bar, I still would rather the shackle be out of the way



No I am saying it is much better to do the opposite, sorry my post you quoted is unintelligible, my bad. The opposite of of what lucky 13 and sputnik posted, wrap bar at bottom of shackle. The lower the relative instant center the better, and the longer the bar the better as well. Trust me, it really makes a world of difference to the climbing ability of the truck.
 
I want to agree with you, however the lower the front of the bar the flatter it will be giving the weight of the vehicle more leverage against the axle, minimizing the x component.
 
Yo busta! Post up a pic of your setup already for those that don't quite understand what you're getting at (like me)...
 
Of course linking is the end all be all, but leafs can work well.

That setup is rad! I have never seen anyone actually implement a link suspension using leafs as the springs, 1/4e excluded. The front shackles are rock finders but the novelty is neat.

My truck is actually currently on jackstands without a rear axle and I don’t recall having pictures of the old setup, when I get around to building the new one I will post up.
 
This picture was taken before the traction bar was completed by FC Fabrication.

yup, that bar along with the entire rolling chassis was built by don at fcfabrication. the shackle is hinged at the top and bottom.

i have driven a cruiser with a short track bar and it definetly makes a difference. you can feel the ass end of the truck lift under acceleration. so like mentioned earlier, the longer the bar, the better. also, the closer to horizontal, the better........
 
Old thread resurrection time: How much movement of the shackle from center (forward and aft) can one expect?

I ask because I plan to build a "swingset" style (for lack of a better way to describe it) shackle on my 81 FJ40 and space is at a premium in the area around the t-case e-brake and gas tank.
 
that all depends on the length of the bar, then length of the shackle,.....but i'd say to be safe you'd want at least 2" of clearance for the top of the shackle.
it's easy enough to bolt the track bar or a mock-up of it in place and then flex out the rig. heck, you can tape a cardboard dummy bar in place and figure it out.
 
Good advice! Thank you! It's about time I got one on there... living on borrowed time everytime I go out and it will only get worse as the springs soften.
Howdy! I highly recommend the track bar. I trashed a diff because I did not have one. I sure do now. I think the 2" is pretty close to the amount of shackle travel, front to rear. It is equal to the change in the length of the leaf spring from dead flat to maximum curve when the suspension is maxed out. I doubt that mine moves +/- 2" from the static position. I welded 2" angle across the top of the frame and then hung the shackle down below that. It has a Heim joint on the lower end of the shackle so it can twist when I get off camber. The bottom of the arm is about 2" lower than the driveshaft so that I can hit/rest on it before I damage the DS. John
 
just tested mine out in the real world over the weekend, no probs at all. old pic but you get the idea
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then flexed
100_2502.jpg


not the best pics but you get the idea
100_2505.jpg


i also built mine below the driveshaft to skid over rock on the trac bar vs the shaft
 

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