You lost me when you said you installed the springs upside down.
I live in Valencia, near magic mountain. Where you at?
Better anti wrap ideas? (1 Viewer)
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You lost me when you said you installed the springs upside down.
I live in Valencia, near magic mountain. Where you at?
Now you really lost me. I'm SOA so if I stick them in the pack right side up or upside down they will raise the vehicle the thickness of the spring.
ntsqd
technerd
Only the overload goes in upside down. Choose one with some arch to it, but not a huge amount. This really only works with SOA since the arc is pointed down. On SUA it would be an anchor digging into whatever, but on a SOA it is up high enough to not be a problem.
With it upside down it does very little for spring rate until pretty late in the travel, but does a lot for keeping the leaves from sharply bending right at the edges of the perch on the axle housing. Sharp bends = kinks = cracks/breakage. It will raise the truck by it's thickness. In my case that was about 1/2"
Once that is in place there are two traction options. The first is to drill a hole in the fwd end of the O/L and install a short bumpstop as a snubber. When the spring winds up the snubber will contact the leaf pack and instantly make the spring rate for the front half of the spring a heck of a lot stiffer. This effectively turns the front halves of the springs into a short traction bar that you can tune by hole placement and snubber height. It's not perfect and it's not for constant hard core use, but it will work for the guy who only gets on it hard on occasion.
The second option is to build a cross-bolted type spring keeper off the rear of the O/L spring that is fairly tall. In most normal movement it doesn't do anything, but on spring wind-up the "keeper's" crossbar is placed such that it contacts the top of the main leaf and limits how much wind-up can happen. The stock leaf packs off my '84 mini-truck are made with this feature.
Ventura
With it upside down it does very little for spring rate until pretty late in the travel, but does a lot for keeping the leaves from sharply bending right at the edges of the perch on the axle housing. Sharp bends = kinks = cracks/breakage. It will raise the truck by it's thickness. In my case that was about 1/2"
Once that is in place there are two traction options. The first is to drill a hole in the fwd end of the O/L and install a short bumpstop as a snubber. When the spring winds up the snubber will contact the leaf pack and instantly make the spring rate for the front half of the spring a heck of a lot stiffer. This effectively turns the front halves of the springs into a short traction bar that you can tune by hole placement and snubber height. It's not perfect and it's not for constant hard core use, but it will work for the guy who only gets on it hard on occasion.
The second option is to build a cross-bolted type spring keeper off the rear of the O/L spring that is fairly tall. In most normal movement it doesn't do anything, but on spring wind-up the "keeper's" crossbar is placed such that it contacts the top of the main leaf and limits how much wind-up can happen. The stock leaf packs off my '84 mini-truck are made with this feature.
Ventura
Thanks. That helps me visualize it better. When I go SOA I think I will go for an A-Frame traction bar to be 100% safe. I'd hate to end up on the trail with a broken pinion. I prefer robust security when out in the middle of nowhere.
Here is what I'm starting with.
I assume you're using Grade 8 hardware in the first pic?
ntsqd
technerd
I don't think you'll get that, but we've been through it already.
ntsqd
technerd
It is all stated above. Just because it is a different vehicle doesn't alter the physics of the situation. The springs should not be changing the pinion angle more than a couple degrees through their total travel range, but an A-frame design requires much more than that since it is a swing-arm and it fixes the pinion angle relative to the arm.
If the A-frame is perfectly centered between the springs and of exactly the right geometry then there may not be any load in articulation, but there most certainly will be excessive load on the 3 bolts at the limits of compression and droop travel. It is not unreasonable for the shear load on those bolts to exceed their strength unless they are huge, but even if they are huge and do not shear there is still the problem of those loads working against other system parts.
The only way that I can see to break a pinion shaft is to bind up the pinion U-Joint. It is a testament to Toyota's design that everything else is strong enough that the pinion shaft comes out the loser. An A-frame doesn't cure the problem, it cures the symptom at the expense of the longevity of other parts.
I probably shouldn't have even posted anything. It seems that when ever this topic comes up people have their pet solutions and all mentioning this does is create strife and discord.
If the A-frame is perfectly centered between the springs and of exactly the right geometry then there may not be any load in articulation, but there most certainly will be excessive load on the 3 bolts at the limits of compression and droop travel. It is not unreasonable for the shear load on those bolts to exceed their strength unless they are huge, but even if they are huge and do not shear there is still the problem of those loads working against other system parts.
The only way that I can see to break a pinion shaft is to bind up the pinion U-Joint. It is a testament to Toyota's design that everything else is strong enough that the pinion shaft comes out the loser. An A-frame doesn't cure the problem, it cures the symptom at the expense of the longevity of other parts.
I probably shouldn't have even posted anything. It seems that when ever this topic comes up people have their pet solutions and all mentioning this does is create strife and discord.
Why that attitude.
I see a lot of stuff that people have done and I think it is just wrong for certain applications. Some of the designs may be OK for the drag strip but not for a rock crawler.
I just want to do it right the first time.
I value your input but pictures would be great.
I see a lot of stuff that people have done and I think it is just wrong for certain applications. Some of the designs may be OK for the drag strip but not for a rock crawler.
I just want to do it right the first time.
I value your input but pictures would be great.
ntsqd
technerd
Maybe it's my perception, but it feels like I eventually get grilled and then raked over the coals when ever I post on something like this. Answering why I think it is a better design is one thing, but feeling like a target is different. Perhaps it is my wording that causes this, but it is not intentional.
I might be able to turn up the jpg of the plot that Lars generated in SolidWorks. Since the spring lengths are different, the numbers on that plot would be useless to an FJ and removing the numbers makes a plot that looks like the qwikie that I posted above somewhere. There is a decent pic on the EB vendor site of the single bar link.
Did that answer the need for pics, or have I missed something?
The most telling thing would be for a truck with an A-frame to be lifted on a hoist allowing the axle to droop to it's limit. Then try to remove any of the bolts holding the A-frame in place. Then fully compress the suspension (short of removing all but the main leaves I'm not sure how you'd do that) and try removing the bolts again. IF the A-frame isn't under a torque load from the power train and it isn't causing other parts to be abnormally loaded then the bolts should slide out without any trouble.
I would be very surprised if they did. Extremely surprised.
For me it comes down to this:
An axle solely on leaf springs travels in an arc, but with a fairly fixed pinion angle relative to the ground. That is to say that the axle housing does not rotate much. There is very little fore to aft change in axle position compared to the travel range.
An A-frame is a swing-arm, the axle end travels in an arc and the housing rotates the same amount as does the swing-arm. The pinion angle will vary greatly relative to the ground.
Those don't mix together very well without other ingredients.
If the axle housing is rotationally and fore/aft floated on the springs (or the springs are double-shackled) and that A-Frame's forward pivot point is very carefully chosen, then they can work together with only a slight bit of binding (because of the non-constant radius nature of the arc of travel of a leaf spring) at the very extremes of the travel range. Which is livable.
EDIT: I am not a rock crawler. I am a desert racer and an explorer. Hard core crawling, like hard core anything else, needs very specialized equipment. I am directing my thinking towards the more general application that sees crawling, but it also sees going camping and exploring. There is a reason that the comp buggies don't use leaf springs, but there is no reason that the rest of us can't.
I might be able to turn up the jpg of the plot that Lars generated in SolidWorks. Since the spring lengths are different, the numbers on that plot would be useless to an FJ and removing the numbers makes a plot that looks like the qwikie that I posted above somewhere. There is a decent pic on the EB vendor site of the single bar link.
Did that answer the need for pics, or have I missed something?
The most telling thing would be for a truck with an A-frame to be lifted on a hoist allowing the axle to droop to it's limit. Then try to remove any of the bolts holding the A-frame in place. Then fully compress the suspension (short of removing all but the main leaves I'm not sure how you'd do that) and try removing the bolts again. IF the A-frame isn't under a torque load from the power train and it isn't causing other parts to be abnormally loaded then the bolts should slide out without any trouble.
I would be very surprised if they did. Extremely surprised.
For me it comes down to this:
An axle solely on leaf springs travels in an arc, but with a fairly fixed pinion angle relative to the ground. That is to say that the axle housing does not rotate much. There is very little fore to aft change in axle position compared to the travel range.
An A-frame is a swing-arm, the axle end travels in an arc and the housing rotates the same amount as does the swing-arm. The pinion angle will vary greatly relative to the ground.
Those don't mix together very well without other ingredients.
If the axle housing is rotationally and fore/aft floated on the springs (or the springs are double-shackled) and that A-Frame's forward pivot point is very carefully chosen, then they can work together with only a slight bit of binding (because of the non-constant radius nature of the arc of travel of a leaf spring) at the very extremes of the travel range. Which is livable.
EDIT: I am not a rock crawler. I am a desert racer and an explorer. Hard core crawling, like hard core anything else, needs very specialized equipment. I am directing my thinking towards the more general application that sees crawling, but it also sees going camping and exploring. There is a reason that the comp buggies don't use leaf springs, but there is no reason that the rest of us can't.
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I'm new to suspension design and I'm following these conversations closely. I'm looking for an anti wrap application for SOA. My main uses will be offroading on hard trails that require lockers and a gas once in awhile to push over things. What designs work best for this? I also use my rig on the road (weekends only, I have another DD.)
I like your input ntsqu but I think your tone rubs people the wrong way sometimes. Your tone can be opinionated and that does get people fired up. I don't mind it and I'm willing to listen to those who have more experience than myself and draw my own conclusions. I would never install or put anything on my truck unless I knew what it would do to the vehicle.
I like your input ntsqu but I think your tone rubs people the wrong way sometimes. Your tone can be opinionated and that does get people fired up. I don't mind it and I'm willing to listen to those who have more experience than myself and draw my own conclusions. I would never install or put anything on my truck unless I knew what it would do to the vehicle.
I could not agree more.
I have snapped pinions on my FJ40 and they never break in the driveway.
I have snapped pinions on my FJ40 and they never break in the driveway.
Amigo, what you say is true.. And, if you built a properly designed 2 link the problems would be negligible. And binding would be minimal..
However, what people are looking for when building a traction bar on a LC is a preventative measure to reduce breaking pinions. A ladder bar will stop axle wrap. Even if it is hard on springs.. That is something that does not typically break on the trail.
The single bar that reduces axle wrap does not eliminate it. Many have broken pinions with a perfectly designed single bar. In a single bar application the leaf is essentially the lower link. And that link will allow for flex on a LC. And pinions will still be bound up and broken.
The design of a single link works well, but not with lower gearing in high traction situation.
I am not attacking you. The more opinions out there the better. You have a lot of experience that is valuable. Don't take my discussions as an attack. they are nothing more than a discussion. As I have said. Many beers have been shared with my best friend in the same sort of discussion. Perhaps, I need to modify my style..
Can anyone give me a link to the ideal anti-wrap setup for a SOA with 35's? If I'm going to do a SOA and I'm going to prevent axle wrap I want to research it and do it the right way. Any good suspension tech as well, I need quality reading. Searching gives me a start but I want more from all you out there that have years of experience. Nothing can beat people who have built and tested their rigs on the trails.
That is exactly what I was searching when I ran across this thread and revived it.
I would love to see what Poser has made and broke as well as 2BadFJ's, Slee, etc. What was thier final design that held up when you have a 6,000lb rig standing on it back tires going up a waterfall ledge geared at 198:1.
I would love to see what Poser has made and broke as well as 2BadFJ's, Slee, etc. What was thier final design that held up when you have a 6,000lb rig standing on it back tires going up a waterfall ledge geared at 198:1.
who else will listen to me
BTW, more info on the single wrap bar on a 40
https://forum.ih8mud.com/40-55-series-tech/107222-traction-bar.html
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poser is SU so he just plain sucks.. Jim has a standard A frame ladder bar.
Slee.. Beats the hell out of me. Does he even have a 40 or 60??
