I don't claim to know a lot about traction bars, so that is why I come here and also ask the manufacturers of said bars.

If the ladder bar with shackles was the preferred method, why are PMF and OUO not making this style?

I have only really seen the Fabtech bars with the front shackle on them, any others that you can link here or suggest?

In addition, if there are shackles on the frame, wouldn't that provide the axle with more than desirable movement negating the entire idea of installing traction bars? I would think that instead of the bars holding the axle in place when it is trying to twist itself off, the shackles would not provide enough resistance to keep the axle in place.

Below is an animation that I found that portrays the arc of the leaf springs when working to return the spring to its normal shape. I see the shackle allows the proper movement of the leaf spring, but in my mind I cannot see how a free floating ladder bar design will allow for the bars to be solid enough to stop axle wrap. I have seen problems with the Fabtech bars, but they could have been abused and bent due to misuse. Are there any other free floating bars out there available to us?



The OUO appear to have a bushing on the frame mount to allow for some movement, but also fostering the single bar mounting method. The OUO may just be the best of both worlds, but comes at a cost.



Again, not trying to knock your idea or view on the topic, just trying to learn and figure out what is the best option for my application. I welcome your ideas and thoughts.

 

The hinged lower link style allows the axle to rotate against a fixed distance to the frame at one height. When you compress the suspension, that forces the axle to twist and changes the driveline angle in relation to the frame. When you articulate over an uneven obstacle, you make one side move forward and the other aft. Is it a big deal at low speeds? No. But it is a compromise.

When you have traditional shackled ladder bars, the relation to the frame is maintained, but the axle can float fore and aft without any impact on the angular relation to the frame in the driveline. This is how a leaf spring suspension is meant to work. The rear of the spring has a shackle to allow the fore/aft motion of that connection.

The problem with most of the drag racing bars is that they don't allow for side to side deviation and reduce articulation. You need to accommodate for the angular differences in relation to the centerline of the chassis with hinges at the axle and frame - which add expense and complexity.

 

Idk why more company's don't make them. Probably because they are harder to fit under most vehicles. There's a mounting point in two places on the axle, and one shackle on the frame. That way instead of needing two bars, one is needed. Think of it like putting a big wrench on the axle tube, holding the end of the wrench will keep the axle from twisting and walking forward. With a single mounting point on a bar at the axle end, it has to be mounted to act like a brace between the axle and the frame to keep the axle from walking forward


Here's a crappy pic of the one on my Jeep.



There's a lot of leverage that gets transfered by running a bar like that. But it allows full suspension movement too. I like to run the bottom bar just below the level of the driveshaft, and have the shackle way up close to the tcase...

 

If I understand you guys correctly you are saying that the single bar method is fine as long as there is no sudden or extreme change in the suspension (mostly leaf springs) while traveling?

I still don't understand how the front shackle on a ladder bar maintains the axle in a state that prevents axle wrap. I understand now how the ladder bar shackle allows for articulation of the articulation on uneven surfaces. Although, I see axle wrap pushing the shackle forward and not solving the problem of axle wrap. I am probably wrong, but that is how I am seeing it in my mind.

I have not really seen any kits with shackles other than the Fabtech bars, but have read too many issues with them to put an order on them. The Pro-comp seems to have a similar frame mounting style as the PMF where there is a bushing allowing for slight horizontal movement during axle articulation.


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I have not seen any kits that have a single ladder bar style that mounts near the differential. Even then, it would be a weld on kit, and I don't have the skills or tools to do the weld job myself, so a bolt on kit is what I am looking for.

 

The ones I designed had a telescopic rotating end yoke and were to be fixed to the axle near the diff. The problem with most vehicles using this design is that there's not enough room to do it. I'll be making ladders with heim joints at all three mounting points, and a shackle to take up fore/aft length variation.

Your animation in the post above is close, but the traction bar is mounted on the wrong side. That gif is representative of how a front axle would be configured if you were so inclined.

The problem with the 2 mounting point bars is that when you brake the axle is allowed to roll forward and down, and when you accelerate, the spring is still being tensioned before the bar does anything. It's an imperfect system, but seems to work to most folks satisfaction.

 

Another high end option is Rize Industries- a buddy has a traction bar system and dual rear shock set up that is totally 'the bomb'. More heavy duty than most of us need! Has floating front mount also, all bolt on.
Rize Industries LLC - Specializing in custom bolt-on suspension lift kits and accessories.

 

I mentioned something akin to this in a PM to Sous this weekend. Take a look at your springs in the rear. They are configured to push the rear axle aft when the springs compress. The animation in the GIF also shows the axle rotating with spring compression, this is counter to the physics of the configuration of the spring mounting points (with a shackle). I see that setup allowing the spring spread with compression - but not the rotation. Our back springs should keep the angle of the pumpkin constant, changing only the elevation of the axle in relation to the frame. Wouldn't ladder bars defy this behavior, where a traction bar would serve it better?

In order for the axle to wrap, the axle (or at least the bottom of the axle) would have to move forward of it's intended travel path. Traction bars attached to the bottom of or below the axle prevent this.

 

I guess easiest way to show how a single bar isn't the best would be to unbolt one end, put a heavy load in the box or hook to a camper, than try and bolt the bar back up. I can almost guarantee that it would not line up.

I ran a set of single bars back in the day, I managed to get stuck in a odd situation and one back tire was hanging in the air and the other back tire was shoved up so the axle was almost on the bump stop. Well that bar on the side where the axle was shoved up was bent where it was easily seen. Once the pickup was back on flat ground, the bend was still there. But you had to look for it. Ever since than I've ran a shackle type bar. Never had a issue with them except bending them due too using too light of material. But they bent in some extreme traction, heavy pulling cases, with tall *** tires.

 

Dave, what material did you use in the ladder bars that bent?


The axle rotating with a leaf spring's travel is an acceptable deviation from ideal. In most circumstances, the spring itself is enough to keep the nose of the pinion aimed in the right direction. We're not using traction bars to retain proper/acceptable driveline angles, we're using them to correct for failure of their ability to keep the axle from twisting the springs and causing other issues. I don't think anyone's ever twisted an axle under a street driven vehicle to the point the u-joint was cogging from too much angularity (I have it happen on my stump grinder I built for my tractor - because I couldn't find a H-coupler for series 7 PTO's). When discussing the pinion nose relation, it's more intended to represent that the spring pack isn't twisted into an S, which is the problem traction bars solve.


Fixing a position on the bottom of the axle in relation to the frame still allows the spring to twist on the front connection. It limits it's available torque to do so, but it doesn't eliminate it's movement. Axle wrap helper devices have tried stiffening this flex for decades.


ETA: The video isn't an endorsement for the roadmaster springs, and I think their installation on the rear would actually make spring wrap worse.

 

I have had this in mind for a while, and plan to perform that very test.

If the single bar is anchored at the precise pivot of the arc, it should work without issue. The fun part is to determine the location of that precise point.

 

Understand my preference is to not use the single bottom bar but that in no way means I won't build a set for my truck.

Since the axle is located by a spring there has to be some compliance as to how the two arcs differentiate. The bottom bar is usually very long, this makes the arc and rate of change not nearly as drastic as the leaf spring arc.
The link though has very low compliance save for the poly bushed end if equipped. The spring under the same loads will quite readily bend and change it's length (that's the reason we need the bar in the first place right).

Another option that would definitely not work for everybody is the style used on mid 90's Explorers.

 

I would go with OUO. They are the only set out there that does everything. This same exact kit can go on any truck, cab configuration, lift height and work...and if you change the height of your truck down the road you can adjust your bars to your lift. If you buy them they are the kind of thing that once you have those parts in your hands and experience the utter joy of opening those boxes you realize that you spent your money well.

The same exact bars go on a 1,000 horsepower truck to a stock truck.

I will tell you to stay away from traction bars that are built with joints, or ones that are fixed length. Joints will eventually fail and will need to be rebuilt....joints also can squeek and annoy the **** out of you. There are threads out there on this issue....LOL

Fixed length bars WILL make your truck ride stiffer in the rear. It will be bouncier. It will reduce the amount of travel as well. Your wife or girlfriend WILL notice the reduced ride quality in your truck after you install them...LOL

The "floating" traction bars with a shackle can still bind and that path of that front shackle will never match the spring travel. I also do not like ladder style bars that have two points of connecting to the axle. They tend to break when in a bind. These are floating style bars....




Here is the set I stuck on My Dads truck. Completely stock and stuck this on in the driveway. You won't regret ever buying anything from OUO.







Here are some videos of them working in action.....

 

Those are spray painted turds.

That's not a heim joint on the bottom, that's an eye bolt. No flex possible in that, so you'll have side to side binding when the axle is off camber.

Based solely on the (extremely) poor welds, I'd also question if those were made of pipe. Pipe is not an acceptable construction material for traction bars. It's soft and ductile (it readily bends).

 

Layson, there is no doubt in my mind that OUO makes a quality product. Although, are they not the single bar method that you warn us to stay away from? Also, I feel that the PMF design is very similar to the OUO design, but this is only my opinion based on my research from my leather recliner looking at pictures.

I think I am understanding the geometry in regards to ladder bars now. The 2 points on the axle of a ladder bar is what keeps the axle from twisting, then the front shackle keeps the axle moving up and down as it should.

The only real option for this sort of setup is the Fabtech, and I just don't think I can trust them to work well with my trailer in tow.

CarterKraft, I have seen the top mounted traction bars but have zero knowledge on if they work or not. The link below is for a set offered by Tuff Country.

1999-2004 Ford F250/ F350 Super Duty 4wd - Traction Bars [20995] | $100.76 | SD Truck Springs | Leaf Springs, Helper Springs and Suspension Parts





I will have to look into these this week to see if they are a gimmick or just a tried and true method that has been forgotten about.

Jim Timber, I installed the RAS on my truck about a year ago because of axle wrap and to help with load balancing when towing my trailer. The rear end does not sag nearly as much now with the trailer attached and the axle wrap was greatly reduced. Although, I feel that when the axle wrap does happen, the RAS does not actually help the problem and may make it worse by providing another spring to push and pull on the axle. They were worth the shot and I looked at it as killing 2 birds (load handling and axle wrap) with one stone. Well, it appears I only wounded the second bird and it has since regained strength and is flying away punch drunk.

Walt, thanks for the link. They are pricey, but the worst part is that they are not offered for our years of trucks unless I missed them. I know that the frame stayed pretty much the same for many years, but if I am paying $1K I would like something designed to work for my truck.

When examining the OUO setup vs PMF I see very similar designs on the frame mounts. They both appear to have a bushing to allow for some movement when the leaf spring is being compressed. How they perform under heavy tow conditions is still a mystery. I do not want to cause any damage down the road, but I have to figure something out and correct the axle wrap when towing my trailer.

If I need to spring for the OUO, that is fine but at this point I don't see how they are any better than the PMF and if they would allow the axle/leaf springs to travel they way they need to during heavy towing situations.

We are looking to upgrade to a 5th wheel trailer in the next year or so from our travel trailer, so I think the axle wrap will only get worse when this happens. Hence why I am on a mission to fix it before we purchase a 5th wheel.

 

Yes those are junk....LOL.... The joints are junk, you don't want joints in your traction bars anyways. They are a bad idea. Those have a shackle/hanger for the front connection. That is how they "Flex"....LOL