ladder bar questions

Ok guys i think im probably over thinking this but how long is to long? The ladder bars that im making are 6 feet long which i didnt think was to bad till i set them up under the truck tonight. My truck is a standard cab longbed so the bars come almost halfway under the cab which is foward halfway point of the truck. In my understanding the ladder bar converts the twisting motion of the axle into a lifting force which trys to lift the truck up which actually pushes the axle down. Correct me if im wrong the closer my front mounts are to the front of the truck the more its going to try to lift the front of my truck. If my thinking is correct wouldn't a shorter bar put more force down onto the rear axle?

Also which is better mounting the front of the bar with just a bushing/heim joint or a shackle?


Thanks in advance

My truck is an extended cab, long box. I made my bars long enough to reach the part of the frame that is boxed. I am using bungs with left hand and right hand threads, along with heim joints with matching threads. I bought my bungs and heim joints from - Barnes4WD.com - Off Road Fabrication Parts and very happy with quality of parts.

The ladder bars intersecting points from the top bar and lower bar combined with attachment points will have a IC of where it is really lifting at and working the fulcrum point ....
Doesn't matter if you attach the arms at the front bumper...if the geometry is wrong... it won't work right...

It'll lift from that point and plant all wrong, or hit real soft... there is more to it then just length, usually less then 38" hits hard, more bar hits soft, then you got the angles

All you're really going to do is prevent axle wrap, you need to that without binding. This is how I make them, they seem to work alright and are about 65" long




Here's a link if you want to see better detailshttp://www.motorsportdiesel.com/storename/motorsportdiesel2/Image-10656408.aspx

Supershafts said:

The ladder bars intersecting points from the top bar and lower bar combined with attachment points will have a IC of where it is really lifting at and working the fulcrum point ....
Doesn't matter if you attach the arms at the front bumper...if the geometry is wrong... it won't work right...

It'll lift from that point and plant all wrong, or hit real soft... there is more to it then just length, usually less then 38" hits hard, more bar hits soft, then you got the angles

Click to expand...

OK sorry im really new to this stuff and everything you just said was completely over my head. If you would please explain to me how the intersecting points of my top and bottom bar has to do with hows its going to lift. Does my bottom bar need to be a few inches longer than the top bar or just the opposite?

For the length is 6 foot to long for a dd that might see the strip or the occasional pull? What should the angles be?

I'm sure i must sound like a complete dumba** to you but ive looked all over and all i can find is an explanation of what they do. I would love to know the actual science behind them. Please school me.

Here are some pictures of the set up that we came up with, We used 2 1/2 inch DOM tubing with some grade 8 bolts, and fully adjustable heims joints on every corner.

Front Mount:


Rear Mount:


Everything wrapped up and painted on truck:

Now I realize these arent technically "ladder bars" seeing as its just single tubing, but ive rode in trucks with both, and they didnt seem to make too much of a difference.

This would be a ladder bar.



Making it as long as you want you would have to make the spread larger at the diff, bottom bar parallel.
Without getting too involved you might need 14" between the top and lower bar at the axle, probably lower bar 8.5" off center and the upper 4.5" off center, i could be a little off on that, then run them forward and you would need a few added struts between them also
You'll also need the pan hard bar also, or if you are keeping the leaf springs you need a slider box.

Ok my top and bottom bars are 10inches apart at the axle. What is a slider box?I was going to make a shackle mount to prevent binding

Slider box mounts to the axle and the springs go thru so the ladder bar can hold the rear still, but the springs can move.

WICKEDDIESELS said:

All you're really going to do is prevent axle wrap, you need to that without binding. This is how I make them, they seem to work alright and are about 65" long

View attachment 28608


Here's a link if you want to see better detailshttp://www.motorsportdiesel.com/storename/motorsportdiesel2/Image-10656408.aspx

Click to expand...

Got any pictures of these mounted up? Also what are the benefits of the double bar design over a single bar setup??

Thanks

Shouldn't the factory shackle on the rear of the leafs prevent it from binding as the springs compress/rebound?

JFlagg said:

Shouldn't the factory shackle on the rear of the leafs prevent it from binding as the springs compress/rebound?

Click to expand...

With a ladder bar, as the body moves up or down, the spring flexes, and the bar doesn't allow it to, if the rear is located more forward of center then as you turn or compress one side it also changes length of the spring...most people ignore this and that'll cause binding and broken hiems, and even not launching right...

So you use the slider to hold the spring and suspend the car/truck and the Lbar transfers power, and the springs also control lateral movement as well.