looking at a 5th wheel toy hauler to buy. my truck has 6inch lift on 35's. will the 5th axles need to be flipped or does it depend on what brand trailer, thanks

 

Have a look here
https://www.ford-trucks.com/forums/1402370-lifted-truck-and-a-5th-wheel.html

 

sweet, looks like i will have the axles flipped.

 

Even if your truck was stock the odds are good you would still have an issue with sufficient clearance between the bed and 5th wheel and geting the trailer level.

Flipping the axles adds a new set of problems. Most of the 5th wheels made use a Lippert frame, and the suspension on those frames has a proven track record of being barley adequate for the job - if people do not overload their rigs. Flipping the axles probably more then doubles the stress on the trailer suspension.

And what toy hauler are you looking for? Unless you are looking at one of the smaller 2 axle TH's, your current truck will be taxed to the max with any of the 3 axle rigs - if it was at factory level. I don't think there is a 3 axle model made with less then a 18K GVWR, so you will b e way over on the trucks rating.

The trailer needs to be as level as possible to get proper trailer braking as well.

 

Why did you say flipping the axles double the stress on the axle?

Steve

 

By flipping the leverage - fulcrum changes on the side loading. Lippert shackles have a proven track record of barely being adequate on non modified frames.
And I said it "probably more then doubles"

 

The reason I posed this question is manufacturers have "flipped" axles for years and I am not aware it has ever created a problem. Is there any documented source that has discussed that problems have been created. It is so standard a procedure it has been done for decades.

Steve

 

I thought most trailers are built with the axles "flipped", like our trucks the weight is supported by the spring directly rather than all the weight hanging off the U-bolts. I can see that the increased C of G would add side load but "probably more than double"? Is that some scientific formula?

 

Issues like this are important for me because if there is a statement that something causes a problem, I always want to know the documentation for the statement in the real world.

There now are lift kits available from distributors trying to deal with the issues created when trucks are lifted, wheels size is increased, and so forth. Although some manufacturers are widely criticized, I often find working on RVs regularly now for a couple of decades, that the problems alleged are really very uncommon and, often one manufacturer is singled out when the reality is, they are so industry dominant they availability dwarfs that of their competitors. That means for example, way more Lippert components are cited than anyone else's because that is almost all that is out there.

For me, the only question of import in these types of posts is what is the documentation this type of problem really exists, regardless of whatever theory is being stated. Then, how common is it?

In my experience, there is nothing to suggest spring or shackles are breaking routinely and the axle recalls of which I am aware were based on rating issues. If my experience is contrary to what is actually taking place and there is documentation to prove that, I need to know it to change my focus and discourse with customers.

My two cents worth,

Steve

 

Steve, are you saying you have not seen a problem with spring shackles, pivots, bolts springs etc not being a problem in the last 10 years?

I am going to pick on one manufacturer, because I only follow one, Heartland.
The frames and suspension are all made by Lippert, not Heartland. Lippert will claim that they build the frames to Heartland specs.

I find it hard to believe any manufacture would spec a frame for failure. Or, any manufacturer will approve a spec destined to fail.
That said, it is absolutely unacceptable that any luxury 16,000 pound + 5th wheel on it's maiden voyage would have the shackle mounts fall off the frame because of the poorest of welds I have ever seen.

At the 2009 Heartland rally, unbeknownst to many of the campers pulling in, Lippert was inspecting the suspension of every rig.
Out of approximately 50+ rigs inspected, 48 had the suspension replaced at the rally, regardless of the in service date (2005 being the earliest).
At the time I ordered my trailer (May 2009), there were many issues I found with either springs collapsing or breaking, shackles and bolts failing etc that I elected on delivery to have MOR/ryde IS installed.

Since joining the Heartland club I have probably seen or read on the HL forum hundreds of suspension issues, only shadowed by the failure of blowmax tires. I have been involved in several temporary or permanent repairs at the campgrounds.

I understand some companies have the axles flipped from the factory, but I seriously doubt many if any would approve a post build flip.
Flipping the axles can work, but it adds additional stress
The proper way if needed would be to add a "box" to the frame adding the additional height. I say box so that the two frame rails can be tied together, cause the frames just are not that strong to have 2-4" added on. That is what MOR/ryde does when they add the IS.

How about aftermarket correct track installation? AFAIK, Lippert is no longer adding those kits with the extra 2-4" of lift those extra long plates add.

I think shock absorber installations could be a whole other thread. How many near horizontal shocks have you seen installed?

The attached picture is a friends 5th wheel on it's maiden voyage. There is just no excuse work like this.
I can't find the pics of another friends 5th wheel that had that ridiculous correct track add on done - which has since failed and was replaced by MOR/ryde IS.

 

Duane,


No, I am not saying I have not seen any. I have seen one shackle failure and two spring failures. Now you provided documentation with an actual picture and I really appreciate that! When I cite my experience, I am referencing my experience in working on my own on-site plus two small used dealerships and one large new dealership. I have never had a call from the local KOA, etc. for this type of failure. I am not attempting to make a global statement as much as reflect on commonality in my world.


Please do not assume I am defending Lippert, I am not. It is just that Lippert is so dominant in the industry the overwhelming majority of us are riding on Lippert components and if we are not yet, they buy out that supplier next week. They are just that big. I would offer the same statement about tires and many other components by other manufacturers.


When it comes to failures, once it is established they take place, my next concern is how often? I know there will be some, what percentage is key. And yes, you are absolutely right, there is never an excuse for shoddy work.


As to over or under axle positions, I really don't see any difference in how they are mounted, but maybe there is and I just haven't realized it. I will try to look more closely when we attend RV shows this winter.


For the record, techs are taught never to modify anything as a liability issue. I personally adhere to that.


Both Stag and Coast (two large wholesale distributors) have lift kits in their catalogs. I haven't used them and cannot state more than that. I have also seen plenty of lifted fifth wheels and have been asked by more than one owner how to get more height.


Now the crux of my position is thus. It strikes me that posts on FTE are for the most part anecdotal. Here is the concluding statement in my earlier post.


"In my experience, there is nothing to suggest spring or shackles are breaking routinely and the axle recalls of which I am aware were based on rating issues. If my experience is contrary to what is actually taking place and there is documentation to prove that, I need to know it to change my focus and discourse with customers."


I intend to continue to request documentation because that is the only way I know to verify problems exist. It is not my attempt to be an A-hole or imply anyone is lying or is an idiot. I really do appreciate you follow-up and the included graphic.


Steve

 

An axle mounted under the spring will exert more lateral force on the shackles / frame than will an axle mounted above the spring.
It's all about leverage..

--edit--
Or maybe you're actually just talking about the axle locator pin and plate?? The pin/bolt should also be reversed if you flip an axle..

 

Yes but - the real issue is whether this all makes a difference in the real world. That is all I really care about. Is there evidence to support the contention that this difference in physics and force calculations means anything to RVers?


Steve

 

It's the law of physics.. The longer the lever, the greater the force imparted...
It does not matter that it's an RV suspension.
If the lever length with the axle on top of the spring is 10" and you impart a side load to the axle to establish your baseline.
Now put the axle underneath the spring and your lever length is now 14"' you will increase the effective side load roughly 40%..

 

What I was responding to was the suggestion that when a manufacturer mounts the axle under the spring they do something different than when they mount it beneath ie. they just don't flip it. I am not trying to deny physics. What I want to know is how much flipping that axle is likely to impact something in the real world.


My point was manufacturers have built RVs with axles about and below the springs for years. Is there a difference in the parts they use depending on the application? I don't know the answer, but again would like to know the actual answer, not assume one way or the other. Are the manufacturers building so close to the design limit. if one flips the axle, they are over the limit?


For a further example, in a preceding post, the assumption is made that the weld failure was due to Lippert's lack of quality control with their welds, rather than the RV manufacturer's use of the frame they purchased from Lippert. This example was offered in responds to an earlier statement I had posted noting I was not seeing frequent problems with suspension components. I don't know the actual answer, but then I thought back over the post and got to thinking. Over the years I have been under literally hundreds of RVs built on Lippert frames and suspensions. Lippert is a huge manufacturer in terms of volume. If they really are doing shoddy welding, why did I not get dozens of responses to my initial post, not just one? I know there could be many reasons no one else chimed in with the same complaint, but by owners of RVs built by difference manufacturers, but knowing the answer to that question would help assign fault for the failed welds.


What I keep pushing for is real world documentation. When someone says, if you do X, Y will follow in a predictable fashion, or X is better than Y, does it or is it? If we could do that, we could give better advice. I don't just want to be right. I want what I post to be valid and reliable!


Steve