HELP! I've got some serious tire wearing problems. I'll run down the history for you guys and maybe someone can steer me in the right direction.

About a year ago I bought a new 29' Sprinter 5th wheel. After the first 1500 miles of towing I wore the inside of the rear tires down to the cords! When I hitched it up, it sat about 4 inches higher in the front than the rear. The reason? My 2004 Dodge 4x4 sits's quite high. When you stood behind the 5er when hitched, you could see that the rear tires were leaning/tilted out at the bottom. I consulted the dealer where I bought the 5er and they said this was the reason for the uneven tire wear...there was too much load on the rear axle because of the angle it was being towed. It made sense to me. They said the solution was to lift the rv so it would ride level...they did not offer this service.

So, I took my 5er to Camping World and they agreed to lift it by welding a 2x4 box tubing to the frame. My springs were already mounted on top of the axle from the factory so "flipping them was not a solution. After the lift job the rv did sit nice and level. As measured from the frame to the ground, the distance front and rear are identical. Problem solved...or so I thought! After replacing the wore out two rear tires and getting the rv lifted, I'm still wearing out the rear tires at an alarming rate. It's not happening as quickly as before the lift...but it is still happening. I just returned from a 2700 mile trip on brand new tires and I can see that the inside tread on the rears is starting to wear. I'd say in another 3-4000 miles they'll be down to the cords. Whew! Sorry the explanation had to be so drawn out.

Anyway, what options do I have here? At this rate I can't afford to use the 5er and replace tires every 3-4000 miles. That's rediculous. Is the dealer liable? Will they try to blame Camping World? I had the problem before and after the lift. Can the toe-in/toe-out be adjusted somehow? Is it possibly to align tires on a straight axle?

I really need a solution. Has anyone had a similar problem? I see rv's going down the road nose-high all the time. Surely everone can't be going through tires at the rate I am???

Any help is appreciated. Thanks!

 

The axel is not bent is it

 

Several things pop into my mind. These axles are pre stress bent in an arc so they will give good tire wear and track and pull straight. Look at your axles to see if the "bow" in the axle tube goes up in the middle. Then look to see if the brake adjustment slot is on the bottom, centered. If all looks correct, you probably have a bent axle tube. On the bigger trailers that weigh a lot, if someone puts a jack on the tube instead of the spring perch you could bend the axle. You should also run a tape measure between the rims to make sure both axles are parrelell, then drop a plumb bob from the king pin and run a tape from the plumb bob to the front axle rims to make sure the front axle is aligned or squared to the king pin. You could also check the toe in by running a tape from R to L tire front side to rear side, make sure you are at the exact same hight. Hope you find your problem. Let us know.

 

I did notice that the axle tube is bowed up in the middle. I'm the first owner of this trailer so I doubt anyone has put a jack in the middle of the axle although it is possible. But if the trailer had been jacked up in the middle of the tube wouldn't I be having just the opposite wear pattern? An excessive upward bend in the axle should make the tires wear on the outside tread...not the inside llike mine. When I look in my rearview mirror while towing, I can tell the rear tires are not running true...they are towed out. I'm thinking the axle may not have been built/assemled correctly. Is there a fix?

 

If the axle is built with a bow in it, how can you tell if it's bent? I have run a string along the length of the axle tube and it definently has an upward bow. Should it be straight when it is hitched to the truck? This is what I don't know.

 

If the axles were moved to below the springs from above, they would have had to have welded the perches on top of the axles from below. If the perches weren't welded on with the axle bow straight up, you could have some toe out because of this. Your mileage must be taking a hit too eh?

 

These axles typically have camber built into them. That's why the term "flipping the axles" is a misnomer. If someone relocated your axles from above to below the springs by rotating them 180*, then the incorrect camber will result in RAPID tire wear.

If you go to Dexter's website, you'll find an axle relocation kit that, among other items, includes new spring perches that go on top of the axle when it's relocated below the springs. The axle orientation should NOT change (i.e., it should not be rotated) when the axle is relocated.

A good trailer fabrication/repair facility should be able to check and correct your axle alignment unless the axle is bent beyond repair.

Rusty

 

My springs have not been flipped. The springs have been on top of the axle from day one. I bought the rv brand new and that's how it was built. When I had the 2x4 piece of tubing welded on the frame they merely cut the shackles from the frame and installed new ones on the new 2x4 tubing. It appears the axle has not been rotated, etc..

I just had a thought. Even though my 5er sits dead level when it's hitched to the truck; do you think if I lowered the hitch one set of holes lower it would unload the rear axle a bit? That's asssuming I have enough bed-to-trailer clearance. This sure would be a slow trial-and error method. I'd have to tow several hundred miles at the new setting to tell if there was a difference in tire wear.

 

My springs have not been relocated. There were on top of the axle since the trailer was new. Maybe the thing was built wrong fron the beginning...not likely.

 

Well, in your first post you said:
So, maybe you're right. Perhaps the axles were installed incorrectly from the git-go. It certainly sounds like something was wrong from day 1.

Why not get the alignment professionally checked and corrected? If there's a problem in installation, bent axle, etc., that's where it should be found.

Rusty

 

I think I'm going to try and battle it out with the selling dealer first. If the thing was built wrong they should be able to tell me and correct it. I don't want to bear the expense of troubleshooting for them. Of course, as a last resort I will. Maybe I'll go look at some same model 5er's and see if their axles/springs are installed like mine. Thanks for the input.

 

If the axle is bowed up in the middle, I don't think it was installed in the wrong position.

I'm no expert, but I just did the "flip" thing on mine, and I noticed when it was jacked up and there is no weight on the axles, they are both bowed up in the middle. They flatten out considerably when the 5er is fully loaded. If one of the tubes was installed upside down, I would think the middle would be bowed down.

I think my first stop would be to the selling dealer.

Who knows, perhaps they will at least offer to pay an lignment shop to check it out... Maybe the trailer builder has seen this before, and has the equivelent of a TSB for a solution under warranty...

 

I hope your dealer will help you, but it's easy for them to say "get lost", because somebody has modified the suspension. Regardless, it sounds like your rear wheels are simply toed out, which seems to happen easily, but is relatively easy to remedy. If they won't help, a trailer repair shop, or alignment shop should be able to help.

 

I think you're right. I'm going to call a shop on monday that was referred to me by Camping World. I just want to get it fixed. The cost of a couple of tires is easily worth the cost of getting it fixed. Thanks for your thoughts, guys!

 

Sorry, I wasn't clear on my previous post, The bow in the axle tube is supposed to go up in the middle. If someone puts a bottle jack directly on the axle tube when the unit is fully loaded, sometimes the tube will bend a bit. You could take a carpenters square and lay it against the side of the rim/tire to see if there is excessive camber. You can use a tape measure to measure toe on the axle. I am sure you will find something out of alignment.Going back to the dealer may or may not be helpfull, just depends on how good of a dealer/service manager they have. I would press them for a new axle and reimbursement for the tires.