Axle wrap??

[SLOChevy]

I have a 91 Chevy c2500 with a pair of deavers which were softened by deaver before I bought them (used). Because of this im getting axle wrap bad and had to rebuild my driveline. I am planning on building a pair of traction bars to slove this problem and before I start I had a few questions:
I have to mount the bars on the outside of the frame because of the gas tank. They well go back and mount under the leaf pack so I will have to put a bend in them in order to have no metal to metal contact at full compression. Also im am cycling about 16" of travel and have a pair of 16" stroke kings and bedcage with the whole setup.
1) Is there a certian length I should make them relative to the driveline?
2) Where should I mount them relative to the driveline pivot point?
3) Any other suggestions or ideas?
Thanks guys
Paul

[matt_helton]

mount them in the location that will cause the least amount of bind. that is the key. there is no cut and dry location. cycle and measure, cycle and measure untill you find that sweet spot. good luck.

[DEZFAN]

You can do it the hard way and try to estimate the arc that you leaf pack makes as it's being compressed and position the axle mount as low as possible and the frame mount in line of an imagined straight flatted leaf pack, with a bar connecting the mounts that will be the same radius length as the leaf pack arc.
Or guess and position the axle mount atleast below the center line of the axle
and the upper mount on the bottom of the frame rail, with a bar around 5ft to be safe.
Poly bushings could absorb the small miss calcs.

Warning: Sometimes I am totally wrong.

Good luck

[orvacian]

I built this one for my Toyota a long time ago when it had stock length deavers on it, it had axle wrap bad but this took care of it completely. The shackle and swivel lets the axle move on its own arc, and a little side to side, but will not let it wrap. The axle can do anything it wants to, except wrap, unlike those articulation-killing traction bars people put on their full size trucks.

http://www.home.earthlink.net/~orvacian/_uimages/antiwrapbar2.JPG
http://www.home.earthlink.net/~orvacian/_uimages/droopy.jpg
http://www.home.earthlink.net/~orvacian/_uimages/antiwrapbar.JPG
http://www.home.earthlink.net/~orvacian/_uimages/articulation.jpg

[steveG]

Here's a pic of the Autofab 2-link on my Bronco.
9106

[SLOChevy]

orvacian,
I like you design. But how important is that middle swivle. It seems to me that the shackle bushings would account for the side to side motion. Also is that a heim that conncects the traction bar and the shackle above your driveshaft? Where did you mount your shackle relative to the driveshaft pivot point?

[ntsqd]

orvacian did what I would suggest. I don't see a pic there, but basically it should be an 'A' shaped arm mounted to the diff housing in two places with the shackle btwn the single end and the x-member mounted to the frame. Usually you can run this type of single arm along side the driveshaft. In some cases you can make the lower tube *just* a little lower than the driveshaft itself so that it can act somewhat as a deflector.

[Stephen]

We've done a little bit of work on the 2 link stuff and I can give you some pointers:

Definitely use a decent size urethane bushing, 1.5" OD or bigger for the BUSHING, not the tube. We like to use a 1.75 on at least one end.

Start dead below the axle tube with the back end of the bar. This gives you the most separation from the top leaf of the spring.

Run the front of the bar to the bottom of the frame rail somewhere just in front of the spring's main eye and you should end up below the main eye a little bit.

We built some mockup slip tubes to test the location and found that it wasn't as critical as we thought since the tubes slipped 1.5" or more (under power) in several locations. This could help you tune in the mounting point a little better.

Here's the pics from an old susp. on my K5. With a 468 and 42's it kept the pinion in line so I know it worked well. The springs are a custom 63" pack on a 7" shackle with 16" kings on top. Pretty similar to yours overall.
I guess I would post a pic but can't now for some reason so here's the url
http://www.offroaddesign.com/images/TTCK5pics/rear%20suspension1.JPG
You probably won't need the clearance bend in the tubes...

[orvacian]

With my setup, the piviot point is not as important because the shackle moves back as the axle moves down letting the axle/spring move almost like the traction bar was not there. The swivel IS needed though. Remember, when the axle articulates the bar will move to the side and down causing it to bend the bar in the middle. I used 1/4" wall 1.5" dom tubing for mine with a 1/4"x3/4" cold rolled rib down the middle. Trust me, it was super strong. I sold it a while back :(

[Stephen]

With my setup, the piviot point is not as important because the shackle moves back as the axle moves down letting the axle/spring move almost like the traction bar was not there. The swivel IS needed though. Remember, when the axle articulates the bar will move to the side and down causing it to bend the bar in the middle. I used 1/4" wall 1.5" dom tubing for mine with a 1/4"x3/4" cold rolled rib down the middle. Trust me, it was super strong. I sold it a while back :(

I agree with your pivot whole heartedly, solid axles typically steer a good bit when they articulate and leaf springs tend to steer a LOT so you have to accomodate that somewhere. The other option might be to run a longer shackle at the front or go to just 2 mounting points on the housing (arranged vertically) so the whole arm could change angle compared to the housing.

[sickrick]

Here is what I do:
#1 Get a piece of aluminum and and clamp it to the frame rail (it should be large enough to cover any area where you think the front pivot could end up.
#2 get a tube (broom handle ect.) to be the link.
#3 put a temporary mount/pivot 3 or 4 inches below the center of the rear axle.
#4 get some different color markers and mark the dummy tube with different colors every 3 or so inches.
#5 swing a arc on the aluminum by holding the colored marker next to the approprate colored line on the dummy link (do this at ride height).
#6 swing the same arcs with the max down travel.
#7 start loading heavy objects into the bed until you are at or near bottomed out, swing more arcs.
#8 You will find that one or more of the sets of arcs meet very close to the same point (this is the sweet spot).

This has always produced good results for me. You will find that more than one of the sets of arcs may be acceptable. Use uerathane bushing and you cant go wrong. Also consider using the same link positions but start the frame links close to the center of the truck and the axle links out by the wheels as this will help keep the axle centered under the truck and will make the truck handle alot better.

That link thing is genius and would work great also.

[SLOChevy]

Just wanted to say thanks for all of your guys help. Got some great ideas now and hopefully I can find time to get it done for the 1000. See yall in November!!
Paul