you made some very drastic claims, this is a better post to suit your explanation.
LLY: Traction Bars recommendation for heavy towing
- Thread starter NevadaLLY
- Start date
you made some very drastic claims, this is a better post to suit your explanation.
There is no doubt that there are very different perceptions of NVH between people. My brother has a fairly highly modified 7.3 CCSB with traction bars. He'd tell you that it rides perfectly; I'd tell you that it rides like a brick shit-house. And it's not just his truck. Every truck I've ever been in with traction bars (easily 20+), I thought rode like crap compared to a factory, untouched leaf spring setup. Like I said, I recognize that I'm certainly on the more sensitive end of the spectrum.
And as far as the poly joints go, we run back into the same thing as with backing off the Caltracs a few turns. If the joints are flexible enough to allow for deflection and a smooth ride, then how much are those same joints allowing the axle to wrap when torque is applied? It's all a compromise.
I think in a case like the OP's, where you're not only looking at normal up-down axle travel, but also up-down axle travel at two significantly different nominal points (loaded & unloaded, a difference of 2.5"-3" he says), there's no way it's not preloaded and stiff at one of those two conditions. Which means he's either going to be adjusting it constantly, or it's going to be a rough ride (by my definition anyway)
Again, some people can tolerate the decrease in ride quality more than others. And some would value the rigidity of the setup over ride quality anyway.
I probably should have been more specific rather than assuming everyone else would assume that my comments were targeting the OP's situation.
Curiosity question: what is 8 turns of preload accomplishing other than changing the pinon angle and increasing the leaf pack's effective spring rate?
in the off road world, the change in suspension height is NOTHING compared to them and they have been using the "2 link" setup for decades.
the difference is very minor. besides, put a shackle on a single ended bar nets you nothing. you need a triangulated if you want that.
perfect example, class 7 and 7s and other leaf sprung classes use shorter bars than anything considered here (much more arch change through the bars travel) and suspension will move anywhere from 15-20" of wheel travel. These bars mounts just as others you see but only go the length of half the spring (frame end connects just below the front spring hanger much like cal-tracs but solid). What everyone seems to keep missing is the fact the axle does not move in the sense that wheel base would stay the exact same through its wheel travel. as suspension droops out, the wheel base shortens (axle moves forward). as it compresses, axle moves backward. Not in a perfectly linear motion either. This is why these bars can work without much spring bind at all but its all on how you set it up. the longer the bar, the more forgiving the setup can be. the longer the bar, the more anti-squat can change as well so there are lots of different things to it but its all on a small scale.
literally splitting hairs on this whole ordeal though.
there is NO axle wrap bar that will 100% stop all axle wrap and move 100% with the springs. your only choice is to run a shackle at each end of the springs and put a 4 link or 3 link under the truck if you want that. But for the bars that move 90-95% with the spring under high travel (95%+ on our trucks), its a mute point.
Sorry to make it complicated. Just looking to make a good setup. I'm never going to sled pull but I will be driving unloaded and regularly fully loaded, hence why I don't want to adjust every time I hook up.
I'm fine building a ladder bar type setup but also curious if anyone has used mcgaughys traction bars? Looks like they are hooked to a shackle to keep geometry during normal travel. Cognito has some similar shackle mounts.. Maybe this is so new most haven't used it or as Chevy1925 says, over complicated. I just think with so many people running these setups, someone has to be in my shoes as well.
CalTracs are not on my radar at the moment as I don't particularly like the setup and they seem like they'll need constant adjustment for a full load.
I'm fine building a ladder bar type setup but also curious if anyone has used mcgaughys traction bars? Looks like they are hooked to a shackle to keep geometry during normal travel. Cognito has some similar shackle mounts.. Maybe this is so new most haven't used it or as Chevy1925 says, over complicated. I just think with so many people running these setups, someone has to be in my shoes as well.
CalTracs are not on my radar at the moment as I don't particularly like the setup and they seem like they'll need constant adjustment for a full load.
Think of it this way. Have someone start your truck and go from park to reverse to drive. Watch how much your axle moves. Now think when you actually apply power how much more your axle is going to move, it’s going to wrap. Is that causing any problems now, no it’s not unless it’s wrapping to the point of putting to much angle on the drive shaft. The axle is moving inches. Now install normal traction bars, how much is your axle going to be forced to move with 10” of travel maybe a 1/4 of an inch, it’s not going to matter. The ride isn’t going to be any different compared to cruising down the interstate or accelerating down the interstate without bars.
The McGaughy's bars are ultimately very similar to Caltracs when it comes to their downfall (if you call it that). If you have that stop bumper backed off so that they don't bind, then the axle will have to wrap before they contact and do anything (same as backing off the preload on the Caltracs). As I mentioned earlier, I don't think there's any issue with that for a typical street truck. But in the end, you're in the exact same boat for 2.5x the money.
Or, if you have them setup to always be contacting, then you'd might as well just run standard (cheaper) long bars.
If I was looking to buy something (or have something for some inspiration to build your own), I'd look at the Glacier Double-X bars (though I'm a little skeptical of using round tubing in a bending stress situation like they're in). I don't think they make any for a Duramax, or at least don't advertise, but that's probably the best off-the-shelf setup with minimal compromises (in my opinion), other than cost and weight.
That is 100% patently false.
Go put a set of long bars on a factory height unloaded truck, and set them at a neutral preload for that height. Then, put 3k pounds of pin weight on it like the OP is saying he does, and don't adjust them. Go drive it down the road and tell me A) if it rides as well as unloaded with the bars, and B) if it rides as well as it used to loaded without the bars.
There isn't an honest soul in the world that would tell you that it does. I've been there, done that, towing a 14k trailer halfway across the country in a truck with long bars. We stopped mid-trip and took the things off it rode so bad.
As I mentioned before, some people clearly have more tolerance to those things than others. But saying that it'll ride exactly the same is absolutely not true.
Like said above, that is extremely over complicating it. Just make a set of nice long bars with quality joints/bushings and you'll be fine OR buy a set of caltracs. Take your pick.
I would 100% disagree with your statement. If your truck rode that bad that you had to take the bars off then you had them designed completely wrong. I have towed a 14k 5th wheel with my LLY that I built the bars on and noticed a minor difference in overall ride quality. Use high quality parts. Sure the poly races in the Ballistic joints allow for some flex but its MILES less than the factory suspension in regards to axle wrap while still maintaining compliance for articulation.
yeah im with brad on this one. like i said, i carry 2500lbs pin weight and when i do pick ups with my truck i can have up to 6k in the bed. My leafs are literally inverted by a few inches as i dont run bump stop extensions. there is no leaf distortion and unless i adjust my shocks, its a 1970s floaty cadillac ride going on back there. i have two other buddies with bars that say the same thing.
i purposely took air bags OFF my truck because it rode like shit with them on and the trailer on or off the back. with the trailer on the back and no bags with axle wrap bars, its smooth as butter. 0 preload at unloaded ride height.
you had some other issues going on sneaky.
i purposely took air bags OFF my truck because it rode like shit with them on and the trailer on or off the back. with the trailer on the back and no bags with axle wrap bars, its smooth as butter. 0 preload at unloaded ride height.
you had some other issues going on sneaky.
So as an update, I went ahead and just installed traction bars from longhorn. Construction is good and I went with their heaviest duty, pro grade hardware and brackets. Everything was straight forward and the truck runs perfectly unloaded. I’m actually shocked how much of an improvement there is. It’s possible I didn’t realize how much wheel hop there has been because it’s always been there, but with it gone= a whole different truck.
I’ll be towing a full load tomorrow 20k with 3100 on the truck. We’ll see if I need to adjust any preload. :thumb:
I’ll be towing a full load tomorrow 20k with 3100 on the truck. We’ll see if I need to adjust any preload. :thumb:
Sorry for the delay everyone. I made the first tow with the traction bars both on road and off. I had a very slight adjustment after the trailer was on the truck which i have maintained off the truck. Essentially the truck has a pinch of preload unloaded, but nothing loaded.
Results are great. No bucking, no binding, power going to the ground! :woott:
Results are great. No bucking, no binding, power going to the ground! :woott: