Home Made Traction Bar Build

SSpeeDEMONSS

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Sorry, don't mean to derail but reading this thread got me thinking. If bar length is so important to avoid binding, why are there different length bars for different cab/bed configurations when the springs don't change? Shouldn't the spring determine the arc at which the bar swings?

Garrett

probably getting paid at work to post this from my bionic
 

ford rules

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I honestly dont know. And I dont think anyone really does on here, or if they do there not saying atleast. If it was a known thing then the info on lengths would be readily available by searching much like all the other info on here. Traction bars seam to be a grey area though as far as info goes. Im just hoping for the best really...
Got one front mount cut out and tac welded together needs cleaned up still but mostly done. Also bought a new drill and im lovin it so far has a lot of power.
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ford rules

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Thanks^!!
Got one side done and welded im pretty happy with how both mounts turned out what do you guys think?
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VanoFord

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Very slick dude! I can't wait til it's all done and mounted to be out through its measures. Very good craftsmanship.
 

ford rules

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Just asking any reason besides preference for heim in the back bushing in the front?

Bushing at the frame helps stop road noise/vibration, thats my theory atlleast. And I wanted the smaller joint at the axle to make the mount a little smaller an have more clearance. Been running this setup on my ranger for about 2 yrs now on my front 3 link and i like it so i did the same here.

Very slick dude! I can't wait til it's all done and mounted to be out through its measures. Very good craftsmanship.

Hoping to have it done this weekend and will report back!! Thanks guys!
 

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Both rear mounts are welded on the axle driver side frame mount is done and bolted on. Just gotta make the pass side frame mount and cut my tube to length and weld the bungs in then i can test em out.
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Betarocker

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Sorry, don't mean to derail but reading this thread got me thinking. If bar length is so important to avoid binding, why are there different length bars for different cab/bed configurations when the springs don't change? Shouldn't the spring determine the arc at which the bar swings?

Garrett

probably getting paid at work to post this from my bionic

The point of the traction bars is to keep the pinion aligned with tail shaft (for one piece driveshafts) or aligned with the front driveshaft on twp piece setups. The nature of a leaf spring is the axle travel path is not an arc pivoting on the hanger, but a polyarc with the virtual pivot location constantly moving in space. To deal with this, the driveshaft has a slip joint that allows the driveshaft to shorten or lengthen as the axle goes through its convoluted travel path. I farted around with CAD a while ago to figure out where the pivot point would be and though it varied depending on what part of the suspension cycle the axle was on, bar length would need to be approximately 12' long, with the pivot point moving 1/2" in its spacial plane.

So why does bar length vary? Mounting options play a role in how long a bar can be. The longer the bar, the closer to the virtual pivot it will be. Depending on the mounting design of the bars, a long bar can have some flex to deal with the shortening virtual length.

As to the question of the spring determining the length of the bars....the shackle length affects changes to the virtual pivot location as much as the overall length of the spring. Regardless of the spring lenth, there is no practical way to to mount the ideal length bar as it would be somewhere near the front axle.
 

VanoFord

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The point of the traction bars is to keep the pinion aligned with tail shaft (for one piece driveshafts) or aligned with the front driveshaft on twp piece setups. The nature of a leaf spring is the axle travel path is not an arc pivoting on the hanger, but a polyarc with the virtual pivot location constantly moving in space. To deal with this, the driveshaft has a slip joint that allows the driveshaft to shorten or lengthen as the axle goes through its convoluted travel path. I farted around with CAD a while ago to figure out where the pivot point would be and though it varied depending on what part of the suspension cycle the axle was on, bar length would need to be approximately 12' long, with the pivot point moving 1/2" in its spacial plane.

So why does bar length vary? Mounting options play a role in how long a bar can be. The longer the bar, the closer to the virtual pivot it will be. Depending on the mounting design of the bars, a long bar can have some flex to deal with the shortening virtual length.

As to the question of the spring determining the length of the bars....the shackle length affects changes to the virtual pivot location as much as the overall length of the spring. Regardless of the spring lenth, there is no practical way to to mount the ideal length bar as it would be somewhere near the front axle.

I'm a CADD Designer. Might I get a copy of your file to check things out? What you are saying makes total sense. Thanks for breaking it down in suck detail.
 

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Well i got them finished up late last night, just gotta get the bars painted now. Im very happy with how they feel on the truck shifts are firmer and more positive cant feel the axle trying to walk around under heavy acceleration either. They are quiet with no squeeks or rattles or anything. I am anxious to hook the tralier and haul our bobcat as that will be around 10,000 and see how it feels. I have about 60 miles on em so far so i will keep updating as i put more use on them.
For total cost it ended up around $150 that is for 2 2.63'' ballistic fab bushings one 7/8'' heim joint i already had one laying around, then just the tube adapters, jam nuts. All the steel i used i have got for free as well as all the mounting hardware. I also have another $35 for 3/4'' u bolts but thats cause i pulled the rear blocks/ overloads.
 

bad12jr

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Do you have any safety chains to go under the front in case you break a joint or bar?

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lawnguy

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I was also wondering how to figure out the proper length of traction bars for my 04 eclb. I don't understand all of the principles like Betarocker does but is it possible to tie a set of t bars from the front axle and rear to a common mount in the middle(not exactly the middle but somewhere under the cab) so as to obtain closer to the 12' optimum length as mentioned or wouldn't this achieve the goal? I need to build a set for my puller so I don't know if my application would be a great deal different. Any input and advice would be appreciated.
 

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