Looks like alot of guys plan to add traction bars for next season pulls. I thought I would try and discuss some pros and cons of diffrent setups. I dont pretend to be the expert here, just want to share some ideas and see what people think. I plan to fab my own so just looking for some ideas.

I think most guys (street class) use 2 mounting points. One at the axle and one at the frame. This seems to do the job but, now you are relying on the traction bar AND the leaf spring pin (inserts into the leaf spring perch) to hold the axle from rotating. I have seen leaf pins shear off or oval shaped holes in the perches. Because of this people will use 3 points, 2 on the axle and one at the frame (ladder bars). Problem with this is when the rear suspension loads up and squats it changes the angle of the pinion to tcase relation. To fix this pguys will use axle to frame bump stops with 1" clearance. The suspenion squats 1" and the bump stops prevent the suspension from squating anymore.

Finally to my question (if your still reading), Ive never seen this done and its just an idea. How about using the standard 2 point traction bar mounted to the frame and under the axle. This controls the bottom of the axle rotating forward. Now how about using the frame to axle bump stop as a another traction bar to not only allow the 1" of suspenion squat but also to control the top of the axle from rotating backwards. Do you follow me?? The frame to axle link would have to be flexible to allow up and down movement but not allow front to back rotation. Make sense?? Opinions?? Other ideas??

 

Another way to do what you are talking about is to fit a linkge from the top of the axle to the spring mount. You would have to drill a hole in the spring mount and work way to mount on top of the axle. This would allow the spring to work and still use a traction bar at the same time. The axle and linkage would move in unison.

..PT..

 

How about something like THIS.

Brad

 

You are talking about having the ladder bar attached to the axle in 2 places and the front end of the bar instead of being attached to the frame it is attached to another bar going aft that is attached to the frame near the axle centerline right? in a sort of elbow arangement. It could work But it is going to put the same stress on the spring center pin as the 2 point link and possibly bind up and limit suspension travel because the frame mounted bar is going to be pushing forward and down on the pinion during compression and the spring is trying to move the axle back.

 

Personally I dont like the Caltracs system for a truck that pulls a sled. It still relys on the spring center to control the top of the axle which I dont like. Also, the angle of the trac bar in a drag car will be flatter than if it were used in a truck. Especially if the truck has any kind of lift. Because of this angle I think you would change your center point and create more anti squat. That is why you see pullers with 7' long trac bars. The flatter the better.

Let me explain my idea a little clearer to help make sense. I still have 2 points on the axle and 2 points on the frame using 2 seperate links. The first link is a a typical trac bar running from the bottom of the axle to the frame about 6-7' in front of the axle. We have all seen thses before and many people have had great success with them. My arguement is you are still relying on the spring center pin to help control the top of the axle. The second link is the confusing part. We have all seen the adjustable axle to frame bump stops that the pullers use. This limits the amount of squat the truck will have under the weight of the sled. What I am proposing is using this axle to frame bump stop as the second link of the trac bar system. Picture this, take some square tubing like a female receiver hitch and bolt or weld it to the frame perpendicular to the axle. Now insert a male sqare tubing inside, dril some holes at various heights, install a pin and now you have an adjustable bump stop. Follow me. Now how about welding another female square tubing to the axle. Now insert the male tubing into both females and now you still have an adjustable bump stop. Plus, now you have a solid link that will control the top of the axle from rotating. This link would be flexible up and down but solid from front to back. Now not only do you have adjustable bump stops but now you have a trac bar system with 2 attachment points on the axle. Of course this would only be used in pulling applications where you have to have a minimun of 1" suspension squat. When your not pulling take out the male tubing insert and now you have full suspension travel.

Whatch think??

I dont pretend to be the genius here so if Im wrong lets discuss it anbd see what we can come up with. No secret squirrel sh_t goig on here.

 

The twisting action is controlled by the spring u-bolts as well (By clamping it all together). Then the spring itself helps to control movement.

Where would you locate the female tubing at on the axle? There's very little room between the tire and springs to allow attachment (I think?).

 

Yes I understand the ubolts and the spring center pin help control the wrap. I think by adding another link it would eliminate some of that stress placed on the ubolts and pin. Whether its needed or not could be another discussion.

I would mount the female tubing inside the frame rail and inside the leaf springs on the axle.

 

what your describing doing, with the square tube between the top of the axle and frame would work to control the axle movement like you want. The only problem I see is that when the rear suspension compresses the axle moves toward the rear of the truck, and by your method of eliminating axle twist you are also eliminating front and back movement of the axle. So like you stated, this may work with only about 1" of available suspension compression, but even at that the suspension will probably still begin to bind.

Question: I dont know alot about sledpulling, but how would 1" of suspension compression be beneficial? I have heard of people strapping their axle solid against bump stops to allow no rear suspension movement?

 

THe point of no travel is so that all of the weight from the sled pulling down is transfered to the ground for better traction.

 

I think with 1" suspension compression the rear axle would move hardly at all. Even it it did bind it would be minimal. Plus I think the bind would be placed on the links and not so much the suspension.

Basically the 1" rule was put into place so guys dont block their suspension. In other words link the axle to frame with a solid link so the suspension does not have any travel at all.

 

Seems like it would be just as easy to add an attachment point on the top and bottom of the axle tube and use either a 3-point ladder bar or trailing arms (dual) traction bars to control the twist?

I'm afraid you'de get binding with the above mentioned setup when it comes under full load of the sled.

That's just my thinking though, and no one ever accused me of being a genius either .

 

Any traction bars are better than no traction bars.
Traction bars will save you some big money if you are pulling and get you some footage!

 

ok, now I understand the 1" rule. with the square tube traction control method and only 1" of compression travel the bind would be very minimal and the axle rotation would be controlled like you want it to, but, why not use a ladder bar style traction bar with a single frame attachment point and 2 axle mounting points, one above axle tube and one below, (per side). in conjunction with some kind of bumpstop to only allow the 1" of suspension compression. this setup seems like it would work better than the square tube between axle and frame and also would not bind as much, if at all if designed correctly.

 

The set-up that I am building right now is a little different than most on here have mentioned.

Picture this-

Ladder bar system taperd (triangle shape) from 10" apart at the axle to being together where the they mount up to the frame with stringers between the bars making them fixed. At the axle I am welding brackets to bolt the fixed bars to there for when the axle wraps it will force the long traingle shapped bars down. At the frame I am making a bracket to hold a shackle (almost like that of the shackle on the leaf springs). Anyway, the shackle will mount to this backet hanging down and the traction bars will mount to the shackle. The theory behind this is that the susupension will still be able to move up and down (I would rather have the over load springs hold the weight of the pull sled than the bump stops because I have actually almost literly spun out in the exact spot the bump stops made contact). So it will let the suspension move up and down, flex and also let the axle move forward and backward but because of the shackle....it won't let the axle twist or wrap.

I am just in the midst of making this so as of yet I don't have pictures but will in the next few weeks.

Thanks...Ryan

 

I have this type of traction bar in my 73 bronco. I have been very happy with it. I have had better luck with the trac bar above the shackle rather than below it. I think it depends on how your axle articulates up and down and how the axle moves front and back in relation to that. The important thing is the trac bar has to travel in the same path as the axle and the leaf springs. If it doesnt it will bind and limit travel. I really like this setup in an offroad truck where articulation and keeping all four wheels on the ground dtermines if you make your next obstacle or not. I think you still give up some axle control in turn for more articulation. For a puller articulation is useless. I dont want my axle to move at all so all the force is applied to the ground. I want something that when its loaded it is locked into place.

I am curious about when you spun out because the bump stops bottomed out. Could you explain a little more detail please.