Wheel hop, axle wrap...

[Bill2014]

The orientation of the shocks in parallel won't matter. So C3 equivalent with C3=C4=C5 actually equals 3C3. Three shocks mounted in his orientation will result in 3 times the damping.

[MoparToYou]

The only reason I altered the direction of the shocks was to improve shock boot clearance between the shocks, so I wouldn't have to space them farther apart. The direction of the shock doesn't matter. When the axle rotates forward all three shocks are being compressed, and using the compression damping side of their valving. When the axle rotates backwards all three shocks are using the rebound damping part of their valving. turn any of the shocks around, and the forces are the same, compression damping with forward rotation of the axle, and rebound damping with rearward rotation of the axle. The shocks are virtually the same length and angle as the upper control arms, so they just follow the upper control arm through its arc, more or less, during normal suspension movement. It is only when the axle tries to rotate forward and backward (axle wrap) that these shocks come into play.

I went for a test ride. I drove twenty miles of dirt road that included several large smooth wash crossings that function as big G-out bumps, to fully bottom out both front and rear suspension. You can't tell a difference in ride quality with triple kicker shocks, compared to one kicker shock. I had to drive through a drainage ditch at an angle to get around a cable that was stretched across the paved road, because the paved road I wanted to drive is closed from Dec. 1st to April 31st due to snow. I disconnected the front sway bar and fully flexed out the suspension, and the triple kicker shocks made no difference what-so-ever in suspension articulation. I then drove up the 10,000 ft high mountain that I live at the base of, until I hit snow, to see how the truck did.

The triple kicker shocks eliminate about 70% of the REAR axle wrap / hop that I was experiencing in snow. The problem is though, with the rear axle wrap under better control you can push it farther, and then you start to feel front axle wrap / hop. When I complained about rear axle wrap in my first post in this thread on Jan. 7th I did not notice any front axle wrap / hop on that trip. So either both axles were hopping, and the rear axle was hopping so bad that that was all I noticed, or I had not pushed it hard enough to get the front axle to hop. Well now the front axle hops and shakes so hard it makes you think its going to break something for sure. Fixing the rear axle hop did not cause the front axle hop, it just unmasked it, by allowing you to push just a little harder to get it to occur.

So are the triple kicker shocks a cure? No. This truck has a very poorly designed suspension for off road use, at least in snow or sand. Here is a picture from today. I'm not talking about a huge amount of snow either. Before anyone ask, tire pressure was 45 psi. Tire pressure isn't the problem.

[Will]

Tires

[waldo]

Tires

A lot of it depends on the type and amount of snow. It varies a lot, just like mud does. My new one is horrible going up the mountain to my cabin on just a few inches of snow that's about like the shaved ice you get in a sno cone. If you can imagine what I'm talking about.

It just really depends. On flat ground with drier snow it will go through some pretty deep stuff without a problem.

[nts007]

Now mopar here comes the fun one. If. And it's an if. You can find a solid control arm style link with rubber bushings nice and thick. Replace those 3 shocks with a solid. It appears that that would articulate on a nearly identical plane as the lower control arms. But without a truck and only pictures to look at I could be wrong. But if I am correct, then, There should be 0 Axle twist/wrap. Of course if it isn't in a parallel with the control arms then it would be a binding pivot point. I just see such an easy triangulated link setup there. And could remove the track bar then too

[djgaston]

I don't know about all of this jibber jabber, but if somebody needs an arm made for testing, I'll make it. I might even have Johnny Joints that can go at both ends. Need to measure the mounts to be sure. One thing I know for sure, you're not getting rid of the rear track bar without triangulating the control arms a whole lot, with new mounts on upper and lower arms. And even then I wouldn't suggest deleting a track bar on a rig that tows or sees a lot of highway miles.

[MoparToYou]

The triple shock set up that I have reduces rear axle wrap enough that it would be livable. There is still some hop there, but it is much softer and muted, and you could just power through it without worrying about braking anything. I did that in two wheel drive, before the snow got deep enough to need four wheel drive. The triple shock set up really did help the rear end of the truck. The problem now is the front axle, which also has severe axle wrap / hop. And once again, I think it is because of the big soft rubber bushings used on the front radius arms and articu-links. There is no way to mount an anti-wrap shock to the front axle, so "fixes" for the front end are limited. You could change to a diesel trucks front radius arms without the articu-link, but then you would lose suspension articulation. This is a no win situation, with a poorly designed suspension that causes a serious case of axle wrap / hop (mostly axle wrap based on my experience). I've owned countless trucks in the forty+ years I've been four wheeling, and this truck has one of the worst cases of axle wrap / hop of any of them. This truck is worse than leaf spring trucks by far.

What I'm thinking of doing at this point is, ... nothing. And by that I mean not spending one additional dime on this truck. I'll just use it for a truck, and for limited back country exploring. My last truck was a Cummins with 850 ft lbs of torque, and the new diesels are already at 900 ft lbs of torque. Ford has pledged to be the first to 1000 ft lbs of torque, so the torque wars are going to continue. When Ram comes out with their 950 or 1000 ft lb Cummins I'll get one of those (a 3500 with leaf springs) to use for a truck, and use something else for back country exploring. My wife's Grand Cherokee, for example, would have gone right past that little bit of snow that stopped the Power Wagon, with no axle wrap / hop problems at all.

[Will]

In the right scenario an axle welded to the damn frame will hop. I'm telling you it's more to do with the tires and tire pressure than anything. My front will hop in sand with the wrong tire pressure and there is not the first piece of rubber or anything on it to flex. It's all solid joints. Absolutely impossible for it to wrap. However, I do understand where you are coming from and the big bushings just amplify the entire thing but I'm stuck on it hopping and not wrapping and stuck on it being the tires and/or tire pressure. The triple shock is a valid attempt on the back but now that the front will do the same, what do you think now?

[waldo]

I think it's worse on the new trucks just because the suspension is softer and flexes easier than the leaf spring trucks. They can't do everything well and these really fail at snow. Too much weight for the size tire . You'd have to put some big, low psi high float tires on it, but you really can't fit anything big enough to help without a major modification to the truck. Then it wouldn't be good for much else if you did.

I think the powerwagon guys got that suspension dumped in their laps and were told this is what you have to work with. They're selling the nice ride to the on road truck buyers and we just get stuck with the results of that.

[adeluca73]

In the right scenario an axle welded to the damn frame will hop. I'm telling you it's more to do with the tires and tire pressure than anything. My front will hop in sand with the wrong tire pressure and there is not the first piece of rubber or anything on it to flex. It's all solid joints. Absolutely impossible for it to wrap. However, I do understand where you are coming from and the big bushings just amplify the entire thing but I'm stuck on it hopping and not wrapping and stuck on it being the tires and/or tire pressure. The triple shock is a valid attempt on the back but now that the front will do the same, what do you think now?

Will, I'm with you, it's not wrap, it's hop, & it's not a combination of the two either, it's hop. The dynamics & kinematics of the system dictate that, the equations of motion are immutable. Running up long, steep grades in moderately deep snow, at high throttle, with tires at the wrong pressures for the conditions have the potential to exhibit some severe hop---under aggressive acceleration, reduced contact patch surface friction from the snowy trail & the incline grade & you have the ingredients for some tough hop. I'll consider adding two more of those axle shocks or just replacing the single with a different damping factor.

[adeluca73]

An idea to help reduce the front hop you're seeing now is to reduce the rebound rate (velocity) of the front springs by changing the front shocks to something with a higher damping ratio (zeta=C/Cr ). A value over 0.5-0.7 will reduce overshoot by 70%, and definitely minimize loss of traction. The trade off is response time vs. overshoot, luxury cars sit around zeta=0.3, track cars zeta=0.7. As you approach a value of zeta =1, you will experience a very rough ride, but probably minimal hop. I'll try to research the Bilstein site to find damping ratios or damping constant data when Thesis craziness is over

[MoparToYou]

I do understand where you are coming from and the big bushings just amplify the entire thing but I'm stuck on it hopping and not wrapping and stuck on it being the tires and/or tire pressure. The triple shock is a valid attempt on the back but now that the front will do the same, what do you think now?

I've been trying to figure this out for months now, with multiple trips to the back country, and have tried a number of different things to correct the problem. I have bought Staun tire deflaters, and have been using them most of the time. I've been stopped in snow, like yesterday, from axle wrap / hop, gotten out and put on the tire deflaters to air down the tires to 23 psi, and then tried to go again. The axles still wrap / hop pretty much the same. Traction is a little better, but not by much in the hard frozen crystalline snow, and the ride is better, but it still hops about the same. Airing down a 40" tire to 10 psi might stop it, but airing down the stock 33" tires doesn't change things. Tire pressure is not causing it to wrap / hop, that is from a poor suspension design.

I'm not convinced that changing to a coil spring rear suspension for trucks was the right decision. The first half tons Dodge made with coil springs squatted so bad with minimal load or tongue weight that it was embarrasing. Dodge didn't want that happening with the 3/4 tons, so the spring rate is so high that ride quality with coils is only marginally better than with leaf springs. Then they had to do something to improve body roll when loaded, so they changed from a control arm front suspension to a radius arm front suspension. Then they had to add gimmicks to make it work acceptably, like the kicker shock in the rear, and the articu-link in front. I think the original leaf spring design was better, but Dodge is so enamored with this coil spring rear suspension at this point that we're not going to be seeing any changes.

What do I think now? Like I said above, I think this is a no win situation. I had planned on doing 35" or 37" tires, a 1" front spacer lift, rock sliders, a good storage box for the bed, and probably off road bumpers with a better front approach angle. My plans now are to do nothing to this truck. Why spend money on something I don't plan on keeping? I'm sure the truck will work fine in a few months here, when the snow melts.

[loveracing1988]

I think it's worse on the new trucks just because the suspension is softer and flexes easier than the leaf spring trucks. They can't do everything well and these really fail at snow. Too much weight for the size tire . You'd have to put some big, low psi high float tires on it, but you really can't fit anything big enough to help without a major modification to the truck. Then it wouldn't be good for much else if you did.

I think the powerwagon guys got that suspension dumped in their laps and were told this is what you have to work with. They're selling the nice ride to the on road truck buyers and we just get stuck with the results of that.

I hate to rain on people's parade, but it might not have much to do with the soft springs you guys have. My standard 2500 has rear wheel hop pretty bad too. I just noticed it last weekend, it has to be the right conditions I would guess but just a dirt road that had hard packed snow made the rear hop pretty good in 4wd. I backed off to let it settle and then tried again with more gas with no hop, but it is still there even without all the soft coils on the power wagons.

[Will]

I do understand where you are coming from and the big bushings just amplify the entire thing but I'm stuck on it hopping and not wrapping and stuck on it being the tires and/or tire pressure. The triple shock is a valid attempt on the back but now that the front will do the same, what do you think now?

I've been trying to figure this out for months now, with multiple trips to the back country, and have tried a number of different things to correct the problem. I have bought Staun tire deflaters, and have been using them most of the time. I've been stopped in snow, like yesterday, from axle wrap / hop, gotten out and put on the tire deflaters to air down the tires to 23 psi, and then tried to go again. The axles still wrap / hop pretty much the same. Traction is a little better, but not by much in the hard frozen crystalline snow, and the ride is better, but it still hops about the same. Airing down a 40" tire to 10 psi might stop it, but airing down the stock 33" tires doesn't change things. Tire pressure is not causing it to wrap / hop, that is from a poor suspension design.

I'm not convinced that changing to a coil spring rear suspension for trucks was the right decision. The first half tons Dodge made with coil springs squatted so bad with minimal load or tongue weight that it was embarrasing. Dodge didn't want that happening with the 3/4 tons, so the spring rate is so high that ride quality with coils is only marginally better than with leaf springs. Then they had to do something to improve body roll when loaded, so they changed from a control arm front suspension to a radius arm front suspension. Then they had to add gimmicks to make it work acceptably, like the kicker shock in the rear, and the articu-link in front. I think the original leaf spring design was better, but Dodge is so enamored with this coil spring rear suspension at this point that we're not going to be seeing any changes.

What do I think now? Like I said above, I think this is a no win situation. I had planned on doing 35" or 37" tires, a 1" front spacer lift, rock sliders, a good storage box for the bed, and probably off road bumpers with a better front approach angle. My plans now are to do nothing to this truck. Why spend money on something I don't plan on keeping? I'm sure the truck will work fine in a few months here, when the snow melts.

It really sucks man, I wish I was able to witness your truck and help you (everyone) figure it out. I know there's a bad taste in your mouth right now but in reality, the system is preset for an awesome off road machine in my mind. Once someone like Dodge Offroad steps in an builds some johny joint control arms and a couple more things here and there, I think it could be set up real nice. As far as tire size, these trucks work better all the way around on bigger tires. I hope the best for you and hope you can get it like you want.

A couple of questions, do you have any weight in the bed at all? If not, have you tried it with a couple hundred pounds back there? Maybe it needs some to preload things to work right?

[MoparToYou]

I've got a pretty extensive tool set, all of my recovery gear, shovel, axe, brush lopper, an electric chain saw, and my paramedic first aid kit in the back of the cab. That makes for a couple of hundred pounds in the back of the cab, but nothing in the bed of the truck. Plus, the triple kicker shocks have helped rear axle wrap / hop significantly. Adding weight to the bed may not help settle the front axle hop that is now the problem.

[nts007]

Ok so if we are looking at this as wheel hop how can that be dampened. Well we agree that tire pressure plays a role. Why are we forgetting shocks. Shocks dampen and control the vertical travel of the rear axle. So there is a large contributer to the hop. Light high speed dampening in the stock shocks? Maybe mopar was on the right track but it's the shocks that need to be doubled up. Has anyone done a shock upgrade yet? Like 7100s to kings? Lighter tires more or less susceptible to the hop? My leafs get a tiny bit of hop but in reverse only. And even less than a tiny bit at slow speed in snow. But it disappears with throttle. So who's up for shock experimentation.
Also as far as rear triangulation and removing the track bar is gonna take a lot of numbers to get it right. And like you said not so much for towing but quite a few pws have passed the days of towing. The more I read this thread the more I will stick with the kiss method and keep the leaves

[waldo]

I think it's worse on the new trucks just because the suspension is softer and flexes easier than the leaf spring trucks. They can't do everything well and these really fail at snow. Too much weight for the size tire . You'd have to put some big, low psi high float tires on it, but you really can't fit anything big enough to help without a major modification to the truck. Then it wouldn't be good for much else if you did.

I think the powerwagon guys got that suspension dumped in their laps and were told this is what you have to work with. They're selling the nice ride to the on road truck buyers and we just get stuck with the results of that.

I hate to rain on people's parade, but it might not have much to do with the soft springs you guys have. My standard 2500 has rear wheel hop pretty bad too. I just noticed it last weekend, it has to be the right conditions I would guess but just a dirt road that had hard packed snow made the rear hop pretty good in 4wd. I backed off to let it settle and then tried again with more gas with no hop, but it is still there even without all the soft coils on the power wagons.

Well, I have a 3G powerwagon sitting alongside the 2016, so I can compare them pretty easily. The 16 is worse when it comes to the wheel hop.

I'm also not about to dump a bunch of money into a truck I just paid over $50K for to try to fix a design flaw. Maybe, and I say maybe if someone could come up with a real fix, but I'm not about to just go and randomly throw money at it and hope something works by chance.

[olyelr]

I honestly think it has more to do with being an 8000 pound truck in loose terrain trying to gain traction, as apposed to a severe suspension design flaw. They all do it. My 06 3/4 ton had it horribly too. My 2000 dodge half ton did it too. My new jeep jk gets it too.

It will come and go depending on the exact terrain and traction circumstances. Sometimes they will go through the snow like a boss, other times they will hop like a bitch. It just depends. I would be willing to bet if you were following with an older pw with the same tires and air pressure (or any other similarly equipped full size truck for that matter) you will also get hopping.

[loveracing1988]

I think it's worse on the new trucks just because the suspension is softer and flexes easier than the leaf spring trucks. They can't do everything well and these really fail at snow. Too much weight for the size tire . You'd have to put some big, low psi high float tires on it, but you really can't fit anything big enough to help without a major modification to the truck. Then it wouldn't be good for much else if you did.

I think the powerwagon guys got that suspension dumped in their laps and were told this is what you have to work with. They're selling the nice ride to the on road truck buyers and we just get stuck with the results of that.

I hate to rain on people's parade, but it might not have much to do with the soft springs you guys have. My standard 2500 has rear wheel hop pretty bad too. I just noticed it last weekend, it has to be the right conditions I would guess but just a dirt road that had hard packed snow made the rear hop pretty good in 4wd. I backed off to let it settle and then tried again with more gas with no hop, but it is still there even without all the soft coils on the power wagons.

Well, I have a 3G powerwagon sitting alongside the 2016, so I can compare them pretty easily. The 16 is worse when it comes to the wheel hop.

I'm also not about to dump a bunch of money into a truck I just paid over $50K for to try to fix a design flaw. Maybe, and I say maybe if someone could come up with a real fix, but I'm not about to just go and randomly throw money at it and hope something works by chance.

You should have to throw money at it to fix the problem, I agree. I was just saying it isn't a spring issue if a normal 2500 has it too.

[Will]

Ok so if we are looking at this as wheel hop how can that be dampened. Well we agree that tire pressure plays a role. Why are we forgetting shocks. Shocks dampen and control the vertical travel of the rear axle. So there is a large contributer to the hop. Light high speed dampening in the stock shocks? Maybe mopar was on the right track but it's the shocks that need to be doubled up. Has anyone done a shock upgrade yet? Like 7100s to kings? Lighter tires more or less susceptible to the hop? My leafs get a tiny bit of hop but in reverse only. And even less than a tiny bit at slow speed in snow. But it disappears with throttle. So who's up for shock experimentation.
Also as far as rear triangulation and removing the track bar is gonna take a lot of numbers to get it right. And like you said not so much for towing but quite a few pws have passed the days of towing. The more I read this thread the more I will stick with the kiss method and keep the leaves

I agree. What controls the axle? The shocks. Mine would hop bad with the worn out shocks and I can't make it hop in the rear now with the Kings. The front will in the right situation but not near as bad as it used to.

[MoparToYou]

I honestly think it has more to do with being an 8000 pound truck in loose terrain trying to gain traction, as apposed to a severe suspension design flaw. They all do it. My 06 3/4 ton had it horribly too. My 2000 dodge half ton did it too. My new jeep jk gets it too.

It will come and go depending on the exact terrain and traction circumstances. Sometimes they will go through the snow like a boss, other times they will hop like a bitch. It just depends. I would be willing to bet if you were following with an older pw with the same tires and air pressure (or any other similarly equipped full size truck for that matter) you will also get hopping.

We know that they all have it. What the new truck owners have been trying to say is that the new design is worse. I know for a fact that if we had your '06 3/4 ton and my '16 3/4 ton in the same conditions, that my '16 is far worse. I say that because I've owned all those other vehicles you mention, and I know that they do it. The new design is worse, by far.

[azracer]

On my 2009 3G I noticed 90% improvement in axle wrap (shudder) with only the addition of 2.5" stage 2 Kings ten inch travel shocks. The addition of Thuren Atlas LT leafs eliminated it completely with the stage 2 Kings. I switched the shocks to short body 12" travel King twin bypass shocks and the axle wrap return but not as severe as the OEM shudder was. I would say it is 30% of what OEM was. I suspect the shocks being mounted fore and aft was what helped the most with the stage 2 shocks. The bypasses are very shaft speed sensitive and I suspect this is why it returned to the axle wrap problem.

I mention the above because I wonder if shocks will help any on the rear coil equipped trucks. I'm doubtful because both shocks are front mounted on the axle. It may help a little though. Thuren Fox 2.0 shocks may be the ticket. I would ask Don his thoughts.

[Reloaderguy]

Tires, wheels, shocks, springs, geometry...in that order. Rock hard tires, very little side wall flex, excessive dampening to accommodate excessive spring rate, and unequal length arms to resist squat and dive. Leaf spring trucks are different because of actual axle wrap but the theory still holds but with some different variables. This should all align with Mr. Deluca's expert engineering explanation.

[adeluca73]

Fellas, I feel for you all. I sense the frustration, it's palpable, Dodge had some slick PR, a great travelling road show, and really tried to reenergize the RAM brand with the roll out of the new PW's in 2014. They touted all the improvements and benefits the new PW "SPECIFIC" suspension delivered, and took trucks around the country for people to test and oogle over. We all figured FIAT-->Chrysler-->Dodge-->RAM was "ALL IN" on making this specialty vehicle their version of what FURD tired to make the Rapturd, even though the PW's been around since the mid-1940's. Now that we've had 3 years of the new PW on the street, with several owners putting it through all manner of extensive real-world driving situations, the collective "us" are starting to realize all is not 100% great, and maybe the emperor has no robe, but all is not lost.

I really wish I could help out more...I know if I dedicated some serious engineering time to this, I could solve it for most of you, I just don't have the time right now to research the market for the exact right combination of shocks, bushings, and tires/pressure to eliminate the hop. But even if solved, this is not a remedy that doesn't have consequence. To 100% eliminate the hop, I'm confident it will require altering some other on and/or off-road ride conditions & behaviors, some maybe more detrimental to you than the hop. I honestly haven't experienced the hop myself. I run my tires around 55 front/60 rear, I have an ARB quick deflator, but haven't used it much because I haven't needed to yet. I don't live in the mountains out west, so maybe if I was embarking on a 5-8000 foot climb in 14" of snow, I'd see it too; however, I've driven in 20+" of snow, and I can't make mine hope to the point I noticed it. But I am also not a throttle hound either, I just plod along at a comfortable (probably slow to most) pace, and I don't stop once I start in the snow, and my PW has just mushed along pretty well in the deep stuff w/o much issue. So maybe I'd me more motivated to solve this if I was getting my teeth ripped out of my head like MOpar, SnowSled, and Waldo have been lately.

I'm sorry this is so long...

[waldo]

Fellas, I feel for you all. I sense the frustration, it's palpable, Dodge had some slick PR, a great travelling road show, and really tried to reenergize the RAM brand with the roll out of the new PW's in 2014. They touted all the improvements and benefits the new PW "SPECIFIC" suspension delivered, and took trucks around the country for people to test and oogle over. We all figured FIAT-->Chrysler-->Dodge-->RAM was "ALL IN" on making this specialty vehicle their version of what FURD tired to make the Rapturd, even though the PW's been around since the mid-1940's. Now that we've had 3 years of the new PW on the street, with several owners putting it through all manner extensive of real-world driving situations, the collective "us" are starting to realize all is not 100% great, and maybe the emperor has no robe, but all is not lost.

I really wish I could help out more...I know if I dedicated some serious engineering time to this, I could solve it for most of you, I just don't have the time right now to research the market for the exact right combination of shocks and tires and pressure to eliminate the hop. But even if solved, this is not a remedy that doesn't have consequence. To 100% eliminate the hop, I'm confident it will require altering the other on and off road ride condition & behaviors, some maybe more detrimental to the hop. I honestly haven't experienced the hop myself. I run my tires around 55 front/60 rear, I have an ARB quick deflator, but haven't used it much because I haven't needed to yet. I don't live in the mountains out west, so maybe if I was embarking on a 5-8'K foot climb in 14" of snow I'd see it too, but I've driven in 20+" of snow and I can't make mine hope to the point I noticed it. But I am also not a throttle hound either, I just plod along at a comfortable (probably slow to most) pace, and I don't stop once I start in the snow, and my PW has just mushed along pretty well in the deep stuff w/o much issue. So maybe I'd me more motivated to solve this if I was getting my teeth ripped out of my head like MOpar, SnowSled, and Waldo have been lately.

I'm sorry this is so long...

It's not your problem to solve.