Ram 2500 XL for overland / expedition trips

Explorerinil

Observer
Won’t trussing the axle without addressing the radius arms just transfer the stress to the radius arm frame brackets? Soon you’ll be ripping those off.

Maybe I’m not comprehending the physics right, but it seems like a Johnny joint at the frame side (like Carli does it with their spherical bearing) would allow rotational movement there that the bushings don’t. Or are we talking a spherical bearing at one of the radius arm axle mounts in addition to the one at the frame side? Perhaps that would send those lateral stresses onto the track bar alone, but I’d wager it’s easier to reinforce that than deal with the other issues.



That’s too bad, sorry you encountered it.

Going with a completely new axle if they deny warranty? Or gonna have yours re-tubes and trussed? Seems like it’s still salvageable.
You got a point, I never thought of that.
 

silvrzuki77

explorer
Wouldn’t swapping the front over to a 4 link solve most these issues?
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Ravenmad

Observer
Any update on warranty?

No update on warranty yet. :(

My thought is, if they don't warranty it I will pull the front axle assembly and take it to a place in Portland called precision axle to get repaired. Once it is put back into factory spec we will weld a truss into it, reinstall into the truck and put the factory sway bar back into the truck to prevent the front suspension from articulating. You are absolutely correct in the observation that a truss won't fix the problem, it will only transfer the stress to another point.

Carli arms with spherical joints won't in and of themselves solve the problem either. The spherical joints do allow for a less restrictive movement but do not allow for the housing to "twist" per say as it does when one side compresses and the other drops (articulation). I am talking to Cooper about a 4 link high clearance front suspension to replace the factory radius arm design and run a power wagon sway bar disco. with an air operated actuator. It is either that or power wagon radius arm and sway bar disco. with a air operated actuator.

I don't know of a single power wagon that has had the issue of rotating the short side axle tube ( could be out there, but haven't herd of one yet).
 

Ravenmad

Observer
Wouldn’t swapping the front over to a 4 link solve most these issues?
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This 4 link hangs down even farther than the aev radius arm drop bracket though, and for the 4 link to actually reduce binding it needs to allow for the housing to twist or deflect as the suspension articulates. This is typically accomplished in 4 links by triangulating the upper control arms which in my rudimentary understanding allows for the deflection. If the control arms had heavy rubber joints instead of mechanical joints it would allow for the bushing to be compressed to account for the 1/4 - 1/2" of deflection expected when the suspension articulates and puts a "twisting" load on the axle housing.

For example, last year Cooper replaced the radius arm front suspension on Howi. ( 3 link plus track bar = 4 link ) for ultimate adventure and did not have a single issue with the front housing after that. That was with 12" travel shocks also instead of the 10.2" approx. stock and AEV length replacements.

In the end, everything has a strength and a weakness, a benefit and a detraction. At this point I am simply trying to build the ability to reliably travel and explore with my truck, don't need to go rock crawling and won't settle for the mall parking lot on Friday nights to look cool with the ricers.
 

silvrzuki77

explorer
Copy that, I’ve never seen Pure products in person. Sounds like a custom suspension might be the way to go. I did the same suspension setup in my Suzuki samurai buggy back in 06 and the 3 rd owner is still beating it hard. Obvious huge difference between the two lol.


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marshal

Burrito Enthusiast
You got a point, I never thought of that.

the problem comes from the fact that the front axle is suspeneded by radius arms. radius arms are great for ease of manufacturing and street vehicles that dont work outside of the confines of the stock rubber bushings. Thats why Power Wagons got the Articu-link front radius arms, that are double jointed for the upper link. As the axle drops down on one side, the upper and lower mounts are moving in different planes. The Articu-link adds another rubber bushing in there, and disconnects the upper link from the solid stamping of the entire radius arm. A significant portion of the twisting motion of the radius arm is done by the boxed steel section itself, and the remaining load by the rubber bushings.

the only way to get past this is to divide the upper and lower links from each other, whether thats a 4-link with panhard or what, thats what needs to happen - all four mounting points on the axle need to be able to move in their own planes. So far, the only MFG that i know of that accomplishes this outside of the OEM Articu-link's on the PW, is Lewis Built's HD radius arms that use a Johnny Joint and a FK rod end. downside of moving to spherical bearings and rod ends is that they will need to be replaced as the races wear out, and in a truck this heavy, i would say you will be looking at 50,000 mile Johnny Joint rebuilds.

downside to the Power Wagon links is that when the rubber bushings wear out, you are going to get death wobble for sure - and you have to replace the whole arm as i dont believe MOPAR has the individual bushings for sale.
 

Adventurous

Explorer
the problem comes from the fact that the front axle is suspeneded by radius arms. radius arms are great for ease of manufacturing and street vehicles that dont work outside of the confines of the stock rubber bushings. Thats why Power Wagons got the Articu-link front radius arms, that are double jointed for the upper link. As the axle drops down on one side, the upper and lower mounts are moving in different planes. The Articu-link adds another rubber bushing in there, and disconnects the upper link from the solid stamping of the entire radius arm. A significant portion of the twisting motion of the radius arm is done by the boxed steel section itself, and the remaining load by the rubber bushings.

the only way to get past this is to divide the upper and lower links from each other, whether thats a 4-link with panhard or what, thats what needs to happen - all four mounting points on the axle need to be able to move in their own planes. So far, the only MFG that i know of that accomplishes this outside of the OEM Articu-link's on the PW, is Lewis Built's HD radius arms that use a Johnny Joint and a FK rod end. downside of moving to spherical bearings and rod ends is that they will need to be replaced as the races wear out, and in a truck this heavy, i would say you will be looking at 50,000 mile Johnny Joint rebuilds.

^^^ this, this, and more this

Radius arms and bushings at all joints are simply a cheap, fairly reliable, manufacturing compromise that satisfy the needs of 99% of the HD pickup owners out there. There is no way to get around the fact however that they place undue stress upon other components once you push the suspension beyond its limited range.

Without going crazy and fabbing stuff up, the Lewis built arms do a good job at mitigating the physical limitations to the radius arm design. Once your axle is up and running I’d wager a set of those arms should prevent this from happening again.
 

ttengineer

Adventurer
I also agree with the last few posts.

But, it should be noted that this upgrade really isn’t needed for most trucks in the off road/overlanding scene.

If you do a lot of heavy and fast trail riding with heavy rock crawling then it’s my opinion that the upgrade is needed. However, if very light rock crawling is the upper most extreme of your adventures you’ll be fine with the stock set up.

In other words, if you hit places like Moab often and ride the more difficult trails, get the arms.

The Lewis arms are VERY nice and they also add clearance since you no longer need a bracket drop. I’m not sure if they can account for the 1.5 inch forward of the AEV kit though.


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Bret+famx7

New member
Would the fact that it has 42" tires compound the stresses on the axle or is this issue directly caused by the suspension movement? As in my stock 14 Ram 2500 could see the same problem if subjected to a lot of articulation? I know I'm dumb but I cant wrap my head around what's happened. If I'm imagining it correctly, say your looking straight down from the top of the truck. The left side of your axle has been bent towards the drivers side door basically?
 

Adventurous

Explorer
Would the fact that it has 42" tires compound the stresses on the axle or is this issue directly caused by the suspension movement? As in my stock 14 Ram 2500 could see the same problem if subjected to a lot of articulation? I know I'm dumb but I cant wrap my head around what's happened. If I'm imagining it correctly, say your looking straight down from the top of the truck. The left side of your axle has been bent towards the drivers side door basically?

The axle itself isn't bent, but the plug welds holding the axle tubes to and within the pumpkin have broken, allowing the axle tubes to rotate within the pumpkin. This makes it impossible to hold an alignment and has potential driveline implications as well.

It's just an unfortunate reality of repeatedly flexing out a radius arm system at the ends of the travel spectrum. Its irrespective of tire size and could theoretically happen to any of our trucks pushed towards the boundaries of the suspension.

The Lewis arms fix the problem by using spherical bearings to allow free rotation at several of the radius arm joints. This helps mitigate the rotational stress that would, with the OEM arms, get transferred to the axle and threaten to rotate the axle tubes like Ravenmad has experienced.
 

Ravenmad

Observer
Well, it has been a point of contention at the local dealership. For the time being we were able to rotate the drivers side tube back into alignment with the housing, remove the plug welds and re-weld. We then welded the tube to the center casting and re installed the factory front sway bar. I now have to return the truck to the dealership for the recall on the tie rod, drag link and passenger side knuckle assemblies. Waiting on a truss for the front housing and alignment (again). Hopefully we can get it all done in time for Overland Expo West this month. I am absolutely sure that once I have the front fixed and recall work done I will be selling the truck. It has been a great truck, but now I have a very bitter taste in my mouth per say concerning it.

Side note on the continental MPT 81s. A little birdy told me that the tires being sold by Expedition Imports are in fact "Factory Blems", this explains the difficulty with these tires and the reduced cost over msrp. We also upped our tire pressure to 56psi and added centramatic wheel balancers. I still like the tires, I just have to rotate the tires until I find a set for the front that don't pull to the left or right.
 

silvrzuki77

explorer
Sorry to hear your going to sell it. Are you still going to upgrade the arms? Maybe once you get everything replaced might make it better?


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