Traction Bar Delimma

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Just finishing up my traction bar using an FJ80 front torsion bar welded to the rear axle with mega beefy plate, mounted to a removable skid plate cross member made from 1.5" x 1/8" square tubing - the shackle is two side plates mounted to the front torsion eye running down to a 5/8" heim welded into the cross member. My springs are suuuuuper soft and flat! Very similar to what Rusty Dog is running in #8 of this thread: https://forum.ih8mud.com/showthread.php?t=107222&highlight=wrap+bar (actually took pics of his at GSMTR before I think). Note - I'm the first broke pinion that Trollhole posted in #27 of that thread demonstrating how a top mounted bar does not work (thanks Marshall :flipoff2:).

Problem - while the skid plate isn't 100% finished, it's still pretty beefy. Doing neutral drops last night shows that the pinion and front half of the springs are still flexing up a little bit. While my unfished skid cross member might be flexing - we're wondering if it might be because my shackle is mounted over the cross member with a forward rake?

I'll post pics up later tonight I hope - but can anyone attest if they still get a slight amount of wrap with a mega beefy arm?
 
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I dont really know how yours compares to mine in strength, But I think Im still getting a tiny bit of wrap in mine still. Mines mounted to the cross member, take a look



 
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Arrrgh! Late to meet a lady friend and trying to figure out how to use a new notebook to unload these photos!!!

Anyways - you can see where the torsion bar is mounted pretty stout to the axle - just starting welding with gas - sooo much better.

The front mount isn't finished - have to shim the heim bolt with some 5/8" tubing for spacers (or a s***eload of washers).
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These shots show how I've not finished the shackle and it has some side to side play on the heim bolt - and how flat the springs are. Stock axle with Poly axles and WE beadlocks and 39" red labels - kraploads of traction and we're not talking about a whole lot of movement with neutral drops - but having 3 pinions under my belt I'm done with change outs...

Solutions:

1) finish reinforcing skid plate framing where shackle mounts.
2) get the heim bolt shimmed tight.
3) weld on a piece of tubing to the top of the crossmember, make a shorter shackle and run vertical. Current setup is angled forward and long.
4) FJ80 torsion bar is originally mounted under the front axle - maybe the bushings are a tad soft. Run it as is unless they wear - or ditch it and replace with a bar and poly shackle bushings.

Any input valued - just trying to make it as stout as possible - it's not bad - but want better.
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Also - I'm running an SM420 with AA adapter to a 4speed case I built up with 3 speed gears. I had to cut the rear cross member out years ago and was running the rear AA cross member but I hated the leaks. Converting over to an extra mount under the adaptor - it's a 3rd mnt. for torque only.
 

Trollhole

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Disregard my first post I thought the pics in the second post were yours.

Bill I will be the first to say my design is not the best. Cheap yes. I think you have a pretty good design. Your shackle needs to be vertical. This is probably why your still getting the wrap.
 

Trollhole

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Sorry for the multi post my comp at home is also screwed.

You need to get the bottom part of the shackle as close to the crossmember as possible so your shackle is vertical. You can always grind the edges round to still allow for travel.

Oh and I really like the 80 arm. That is really cool.
 
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I agree ,the shackle should be more vertical .I think you might get a bit too much antisquat too with the shackle mounted above the c-member. They tend to work better with them mounted on the underside of the crossmember.(less bounce)
 
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I 3rd the shackle my brotha man. More vertical, that set up seems like it should be beef enough to handle you. Even if you are still getting some flex under load im sure its still not enough to bind the u-joint and send your pinion flying again.

As for testing it. the easiest way is to back up with some speed and mash on the brakes. If your rear springs turn into "S" shapes you still have spring wrap. I doubt they will, at all after you fix your shackle angle...

See ya in a few days at camp brotha...I have a few long nights ahead of me before I leave. I just came in from outside now, I was rebuilding the t-case to throw in tomorrow after work...

Safe travels man and looking forward to seeing you.
 
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Thanks guys. I will weld in a tube Sunday morning and convert to a shorter vertical shackle with poly bushings. Agree with under versus over - but I don't know if I have time to bend up a removable upper mount right now - but maybe... Will see how Sunday morning goes :D.
 
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Got the super short shackle done. Uses a narrowed pair of poly shackle bushings and then the front FJ80 rubber bushing. Slight forward rake - but it's short and simple - holes are so tight the bolts fit super snug. Hoping it allows the side to side articulation I need - but it should.

Did a couple of 1st gear neutral drops and the whole left front of the truck lifts up nicely. The 39" Red Labels left patches on the driveway.

I think I'm set and I'll carry the longer shackle for the left in place heim as a spare :D :beer: :D.
 
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Cool, Was up til 4 am last night working on the rig. Spent hours and hours welding cage and various other parts. I took more than a spool for my wrap bar to welded in place. Ya gotta see the thing its about as beefy as you can make a freakin wrap bar.

Still got work to do tonight, hope to get all done to leave friday early in the AM..


See ya soon brotha.
 
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Cool, Was up til 4 am last night working on the rig. Spent hours and hours welding cage and various other parts. I took more than a spool for my wrap bar to welded in place. Ya gotta see the thing its about as beefy as you can make a freakin wrap bar.

Still got work to do tonight, hope to get all done to leave friday early in the AM..


See ya soon brotha.

Al - we hope to be passing your neck of the woods sometime after midnight. You'll be right behind us. You'll love SC - it's gorgeous this time of year, and if you have any last minute projects - we might be over at Alan's shop finishing up. See ya'all soon...
 

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