R-Pod 192 frame reinforcement and axle swap

[bbelongia]

First post here, please bear with me...

Our R-Pod 192 is in the early beginning stages of this:

https://www.forestriverforums.com/fo...nt-244234.html

Let me start by saying we really like the R-Pod from a user perspective, but after 2 years and about 10,000 miles, it has become apparent that the frame and running gear are a bit undersized for the task given the construction methods used. Disclaimer: this is my opinion based on a mechanical engineering degree and decades of custom fabrication on various vehicle platforms, I am sure the manufacturer of the frame and RV meet some documented standard somewhere and perform just fine under the intended parameters.

I believe there are two issues, one is the frame flex, most apparent where the tongue meets the rest of the frame. Not much tongue tube extension into the frame, and the attachment method is underwhelming. The other is the fact that the weight of the walls and roof are carried by the outer edges of the floor, which in a few spots are not supported adequately (again, in my opinion).

I intend on addressing these as follows:

I plan on putting an additional 2x4x3/16 wall tube under the existing 5 inch frame tube starting just in front of the waste water pipes and running to the point where the hitch intersects the main frame tube, then bend in to follow the hitch tube which is 2x4 tube. This welded to the existing frame and tongue should suffice in stiffening up the frame and tongue to frame areas. That will add around 350 pounds and raise the trailer around 4 inches. To compensate for that, I plan to order a 7000 (or 8000) lb torsion axle to replace the 4400 lb hybrid that is there today. I need to get into the job to figure out the desired arm rotation of the new axle to net out around 3-4 inches of total lift with frame and larger tire radius. The trailer sits a bit low as built, and while I'm not fond of raising the center of gravity, there would be benefits to a little more clearance when pulling out of sloped driveways, etc.

Along with that, I am going to extend and reinforce the outer front of the trailer where necessary with either more/larger outriggers or equivalent to take the load of the walls and roof a bit better. I think I may have the start of the wall working its way loose from the floor on the passenger front corner, I have to get into it a bit more to figure what if anything needs to be addressed.

If anyone is interested in how this turns out, I will take a few pictures and document my experiences. I have taken information from this forum while exploring the purchase of the RV, if this in some way helps someone then it would be worth the effort to give a little back. If there is little interest I will post an update after the next 5000 mile trip.

This is not a plea for warranty, or an ask of "what should I do". I believe this will continue to be an issue, so I want to "fix" it and increase the safety factor in the process, and this is how I am choosing to address it... your situation may dictate otherwise.

Thanks and happy trails.

[jlankford]

I'll be very interested in following your project. Thanks for sharing this issue. We have a 2023 RP-192. We've put about 4100 miles on it so far, and there is no evidence of the problem. The clear silicon caulk joints are still solid and not separated from either the wall panel or the corner molding, so I don't think there has been any movement in this area. Could you share a picture of what yours is doing? The pics in that link you included of the RP-171 look horrendous.

Our unit has the Beast Mode independent suspension, so not the same axle assembly as yours, and the thing already has a very high clearance. I assume the box assembly construction is identical to the non Beast Mode units - I doubt they did anything to strengthen it. But our unit has already been over some pretty rough offroad camping conditions. And our driveway is actually a 1/2 mile steep gravel road which requires 4WD and a slow crawl over some pretty bad washboard. The camper has been up and down that road about 20 times already.

I appreciate you sharing this - I was unaware of the issue and I'll definitely keep an eye on this from now on.

[bbelongia]

I will take some pictures, unfortunately I already dug into the front. The early sign was the front stone guard worked loose from some of the screws holding it to the underside of the deck. I fixed that with a few more screws and washers, but eventually a fatigue crack showed up in the very bottom corner. That aluminum is only .030, but it should not not be moving enough to do that. When 210 lbs of me jump on the tongue, I can see that side wall of the trailer flex independent of the rest. From what I can see, the front most frame supports stops just shy of supporting the outside wall, that' seems to be where the flex is. When I removed the stone guard, I was surprised to see the white fiberglass shell does not go all the way down to the deck in the front, the stone guard is only covering a vapor barrier and some insulation, not much structural that I can find. It's early yet, I need to get into it to figure out exactly is happening.
You are spot on, on the corners where the walls trim into the deck I could see the caulk line on the trim move independent from the wall... not much, but enough. I will take a picture of that.
I think my issue is that I pull over the interstate at posted speeds, in some states the roads are terrible. I remember hitting a road seam where they were prepping to lay new asphalt that wasn't marked so hard I had to look to see if the trailer was still there. Do I think it should hold up to that.. it would be nice it if did... but I may have unrealistic expectations.

[bbelongia]

Progress stalled Memorial weekend due to tornado clean up in the neighborhood... back to the RPOD the past few days.

As I work thru the measurements, I am beginning to forensically guess what has been happening. After running some strings and measuring, I have a bit of bent rear frame on the driver side back of the axle, about 1/2 or more between the axle and the rear.

I know I took a big hit last summer thru some road construction, I am guess that was the cause. But, I think I found a contributing factor.

Took the wheel and tire off to confirm the axle specs before ordering... with no weight, the torsion arm is at about 1 degree down. Axle tag says it's supposed to be 22 degrees down. Called Lippert, they were really quick to say second owner, no warranty... thanks for that. They said it would be impossible to mis-label the axle as a 22 down when it was really a zero. Not sure how they know that, but Lippert was insistent it would not happen. I always thought the trailer rode a little low. From what I can tell, I am down about 1.5 inches in ride height. In writing this it, occurred to me I need to check the passenger side to see if they are the same... How likely is it to have both sides "relax" at the same time? (in a Covid trailer maybe 100% ??)

If anyone else has a RPOD 192 (or any other RPOD) that has a Lippert 4400# torsion axle that could confirm the tag rotation against the actual arm rotation, I would be interested in a comparison from another trailer....

I am guessing that "relaxing" as Lippert put it, has taken away most of the spring rate in the ride, causing the trailer to ride low, rough, and very close to the bump stops, which may be a large contributing factor in the unit starting to shake itself apart.

Lucky us I guess. Doesn't change the plan, perhaps explains how we got here.

[bbelongia]

Update from the weekend:

New axle is now on order, a custom Dexter 7K. Lippert was cheaper, but just couldn't do it after the demise of the current axle.

Here are some pictures that might help explain what's happening...

View of the driver's side rear... you can see the separation starting...



View of passenger front corner. The two trim strips rubbed against each other and polished the paint off the lower. The situation from the front was worse, the side wall would move independent of the floor, which caused the thin aluminum stone guard to crack. From inside, you can see the sliver of light showing thru on the ends about 12 inches long due to the floor sag.







I have confirmed that this is the result of 2 bent main chassis rails, bend is at the axle point on both. That leads me to believe the axle failure was the cause.

Good news though, the tongue and front header are fine, but upon research and seeing the carnage on the internet of bent A frames, I will be reinforcing that area too.

After staring at it for a few hours, the plan is to run a 2x4x3/16 wall tube under the front header, and under the 2 chassis rails to about 4 feet short of the rear. The trailer is currently supported on the corners which the string test has shown to have the main rails dead straight now with the axle and bracket removed. With the new tube stitch welded, it will act as a 9 inch beam. It will lift the trailer around 4 inches total, as I ordered a 10 degree down axle to compensate for the 1.25 inch radius gain of the new 16 inch tires. I pull with a F350 4 door long box diesel, so a bit higher ride height will help as the hitch almost drags the ground currently. I know I'm giving up some stability by raising the center of gravity of the trailer, but others have reportedly done it to many RV trailers, and the new independent suspension from R-Pod shows the tongue under the frame (a much better design too...) which would raise the frame at least 4 inches, so I'm comfortable giving it a go. And, short of replacing the entire frame or at least new rails, it's really the only choice to correct the current issues...

With respect to the A frame, it's actually attached at an up angle with respect to the frame. From the picture, the 4 inch tube goes thru the header centered, so about 1/2 inch up from the bottom. Where the A frame rail attaches to the main rail, it's just a bit up from the bottom. this results in about a 2 inch rise by the time you get to the receiver hitch. So, my plan to bend and wrap the new rails around like a equipment trailer will not work. I have some ideas on how to shore up the A frame, I will take some pictures of what I come up with. It will not be ideal from an engineering perspective, but it will be an improvement.

[bbelongia]

A few pics of the finished product;