Pup wheel alignment

[AndyBees]

I installed new tires yesterday on my new to me used Pup (1998 Rockwood Freedom, model 1640). I noticed that the old tires are both worn on the inside, pretty bad.

Looking at the axle it appears to be swaying up slightly on each end enough to cause very obvious negative camber. The shaft set-up doesn't have any adjustment at all.

Any thoughts on what could be done?

 

[rob2218]

I was told that PUP tires you couldn't even align them?
is that true or false?
this was told to me by an owner of a Tire Store where they sell tires for PUPs all day long?

 

[tsc]

Before you spend a lot of money.

Have you weighed the pup? Make sure your not overloaded

I'm just guessing, I have minimal knowledge about running gear.

 

[Unstable_Tripod]

Axle damage from overloading was my first thought too. If the axle is actually bent I think you'd have to replace it.

 

[medicmike5969]

Beings that you bought it used, check the axle FIRST to make sure that the PO didn't do an axle flip - which if not done correctly, they end up re-installing the axle upside down. Which puts the camber curve on the bottom instead of on the top.

Lay under the back bumper & look at the axle - you should see a slight curvature upwards, if it's downwards - then it was flipped. If the curve is up - replace the axle, because either the spindles or the axle ends are bent & it costs just as much if not more to re-align them.

The ONLY place to take it for any kind of alignment should be a good Frame Repair Shop.

Any questions, please feel free to give me a call.

Mike
248-933-6616 (cell)

 

[arthuruscg]

Andy,
Does your axle have the usual spring or do all you see is angled arms behind the wheels?
If you see springs, Medicmike is right. The previous owner might have fliped the axle upside down to lift the popup instead of doing the correct way of welding new spring perches on top of the axle.

If the axle was not flipped or all you see are arms, you will most likely have to replace the axle.

Alignment:
There is no easy alignment like on a car. For trailers it usually involves cutting and rewelding the spring mounts to correct thrust angle (trailer rolls sideways slightly). If the camber is out, it usually involves replacing the axle.

For tandem axles, there are alignment kits to correct the thrust angle of each axle (total toe).

 

[rabird]

https://www.youtube.com/watch?v=pRyTeqYuGBk

 

[AndyBees]

Okay, thanks for all the comments and suggestions.

I believe Mike hit it on the nail head. I noticed axles in Tractor Supply several weeks ago had a curve in them. My thinking was, surely that curve doesn't supposed to be on the bottom (close to the road surface).

So, upon examining my Pup I noticed that the curve is down. Thus, I should flip it over.

It does have leaf springs. I'm not sure if there is a tab welded on for the springs or not. I need to go examine!

Again, thanks very much!

 

[AndyBees]

https://www.youtube.com/watch?v=pRyTeqYuGBk

Wow! Sort of what I suspected!

Thanks very much!

 

[Fless]

https://www.youtube.com/watch?v=pRyTeqYuGBk

Never had it done myself, but I think that is somewhat how they used to align the old Ford Twin I-Beam suspension system, IIRC.

 

[arthuruscg]

You have 2 options. Flip the able back on top of the springs or have a new set of pads welded on the other side of the axle. Any welder should be able to do it. If you have a trailer place near by you can ask them, but stay away from rv dealers.

Sent from my Moto X using Tapatalk

 

[turborich]

Make sure that the axle isn't simply just bent do to overloading. Even though people call it an axle flip, it's NOT! You take the axle from above the springs and place in under the springs. No flip is ever involved.

 

[AndyBees]

Well, as I looked over the situation today, the springs are on the bottom of the axle.

The two U-bolts (two each side) go thru a half-moon support piece that serves as a clamp. The support piece has a center pin that goes thru the springs. The piece is not welded to the axle.

Considering the amount of obvious negative Camber (can be seen looking at the wheels when sitting on level pavement), if the axle was rotated 180 degrees it would then have too much positive Camber, in my opinion.

So, maybe if the axle is rotated so that the Camber is at about 0 degrees or just a little positive or negative, it would be okay. However, somewhere in the movement, "Toe" is going to be affected.

Anyway, I see about three options.

1. Rotate the axle a full 180 degrees
2. Rotate the axle about 90 degrees (plus or minus a few degrees) to achieve an acceptable setting for both Camber and Toe. The direction of rotation would have opposite affects on the Toe. Rotation forward would result in positive Toe and the opposite direction would result in negative Toe. In other words, one direction would be Toe-in while the other direction would be Toe-out.
3. Or, just leave it alone and expect the new tires to be trashed by the time our 10,000 mile Alaska trip is finished.

There is no RV service shop anywhere close to me that can do the magic as show in the YouTube Link.

So, I'm leaning toward option #2.

 

[arthuruscg]

The axle is designed to flex when the load is increased. So when the popup is empty, the camber should be about 0 deg.

Sent from my Moto X using Tapatalk

 

[AndyBees]

Well, to clarify things a bit, by flipping, I meant "rotate" the axle 180 degrees. Right now, on flat pavement with the Pup empty, both wheels lay in at the top. The old tires were worn badly on the inside edge.... as well as the spare and two extra wheels that came with it.

The axle is bowed (curved) down in the center.... very obvious.

Searches on the Internet tell me the arc (bow) is supposed to be on the top away from the ground. So, over the years of either loading the Pup heavily or wrong installation, the arc is opposite of what it should be.

Rotating the axle 180 degrees doesn't appear to be a major task!

 

[campfreak]

I would go 180°, that should bring it back to original camber, assuming overloading was not the problem. It seems to me that overloading would not bend the axle in the middle, it would bend right outside the spring perches, so I think the axle flip was done incorrectly, as others have said. Dont mess with the toe-in, unless you have to.

 

[tsc]

From the way you described it, it does sound like the axle was literally flipped (not underslung on the springs).

If I may use some carpenter language.

As your looking at your axle currently, it's crown down--looking like a "U" (where as normal, it would be crown up--looking like a "n")

 

[AndyBees]

From the way you described it, it does sound like the axle was literally flipped (not underslung on the springs).

If I may use some carpenter language.

As your looking at your axle currently, it's crown down--looking like a "U" (where as normal, it would be crown up--looking like a "n")

Yep! That's right. The crown is presently down which appears to tip the ends of the axles up causing the negative camber.

Well, for the last three days, I've been spraying those U bolts with penetrating oil so I can break them loose. I hope to do it either this evening or tomorrow.

Thanks for all the input. I really appreciate it. We are three weeks away from departing on a road trip to Alaska. We are leaving on Monday, July 7th. We can leave a little later but no earlier.

 

[arthuruscg]

You will either want to lock tight the nuts with high strength or replace them. The nuts are designed to not back off the axle U bolts.

 

[arthuruscg]

Keep in mind that when you rotate the axle, the spring perches will now be upside down. You will have 2 choices.

1. Move the axle from below the springs to above the springs (stock) and loose about 2-3" of lift to the trailer, and if the tires are larger then stock, you might have rubbing issues.

2. Have new spring perches welded on the other side of the axle. Or if you can find a bolt on kit like listed below. (I don't know the diameter of your axle, so it might not be the correct kit.)
http://www.etrailer.com/Accessories-and-Parts/Dexter/K71-384-00.html

Here is what the perches look like.
http://www.etrailer.com/Accessories-and-Parts/TruRyde/TRSS238.html