What would cause this tire wear?

[Dan50]

Bent spindle.

[TitanMike]

Originally Posted by mxtreme30

Ha! Did not know that! You would think that they would shim the hubs to get proper alignment, but that would be the right thing to do. Just bend the tubes to make it work. Lol. Typical RV mythology. Thx for the insight Mike!

Hard to do if the spindles are welded to the end of the axles.


When that's how they're fastened the right way IS to bend the axle.

[TitanMike]

Originally Posted by nutdriver

I have nearly an identical issue with my trailer. I currently have 10,000 miles on the trailer. All the tires are wearing fairly well except for the left rear that I had to replace this fall. I checked alignment using the method outlined in this youtube video.

Found that my front left axle position was about .5 cm further to the rear. The Left Rear axle was another 1 cm further after from the center of the left front. Thus my left rear axle is 1.5 cm further to the rear than the right rear. It is causing a toe out of 1 cm. Based on some tech responses on eTrailer, that is too much.

I already had replaced all the bushings with bronze bushings and wet bolts along with the Dexter Ez Flex equalizer.

Really debating now what to do to fix the alignment.

To the OP I would start by measuring the alignment as outlined in the linked Youtube video.

One of the problems with tandem axles that use springs and equalizers is that as a spring flattens out it gets longer. Unless springs on one side are loaded so that the equalizer has moved into the exact position as the one on the other side, the axle spacing on the sides may not be equal.

Measuring ride height on each side is important if trying to diagnose axle spacing issues. If one side is lower, it will flatten springs more on that side and since opposite ends of the springs on each side are anchored to fixed points, axles are for all practical purposes changing angle with the TT's center axis. Usually the lower side will have a wider spacing than the higher side.

A simple measurement from pavement to frame @ front and rear anchor points will be a give-away. Shifting weight from one side of the TT to the other may cure the "spacing" issue but I doubt it will cure the wear issue. Only way to restore camber will be to bend or replace axle.


FWIW, the hardest thing to do when teaching mechanics how to perform Wheel Alignments was to get them to measure ride height. Most figured if the vehicle wasn't a Chrysler with torsion bars Ride Height wasn't adjustable so why bother.

Apparently they hadn't heard about replacement springs.

All I can say is that I'm sure glad I moved into a Corporate office and eventually retired.

[nutdriver]

Originally Posted by TitanMike

One of the problems with tandem axles that use springs and equalizers is that as a spring flattens out it gets longer. Unless springs on one side are loaded so that the equalizer has moved into the exact position as the one on the other side, the axle spacing on the sides may not be equal.

Measuring ride height on each side is important if trying to diagnose axle spacing issues. If one side is lower, it will flatten springs more on that side and since opposite ends of the springs on each side are anchored to fixed points, axles are for all practical purposes changing angle with the TT's center axis. Usually the lower side will have a wider spacing than the higher side.

A simple measurement from pavement to frame @ front and rear anchor points will be a give-away. Shifting weight from one side of the TT to the other may cure the "spacing" issue but I doubt it will cure the wear issue. Only way to restore camber will be to bend or replace axle.


FWIW, the hardest thing to do when teaching mechanics how to perform Wheel Alignments was to get them to measure ride height. Most figured if the vehicle wasn't a Chrysler with torsion bars Ride Height wasn't adjustable so why bother.

Apparently they hadn't heard about replacement springs.

All I can say is that I'm sure glad I moved into a Corporate office and eventually retired.

Thanks for the helpful post. I am curious if you have any experience with the Lippert Correct Track system.

[mxtreme30]

Originally Posted by TitanMike

Hard to do if the spindles are welded to the end of the axles.


When that's how they're fastened the right way IS to bend the axle.

I guess it's apparent I know nothing about trailer axles!
Stopped over at E-trailer website and by George all their axles were bent and the description is exactly as you posted.
To me making the axles this way makes it hard to determine if some nimrod jacked his trailer up from the middle of the axle tube, but hey, what can ya' do. Lol.

And for the OP, don't listen to me. Listen to Mike. I'll just stand over here in left field chasing butterflies!

Sorry for the mis-info.

[Airdale]

Originally Posted by hinkle_e

Swung by the storage yard for a few more pics today. Not sure if theres anything else to see in them for diagnosis, but here they are anyway.Attachment 217604Attachment 217605Attachment 217606Attachment 217607Attachment 217609Attachment 217610

Not to change the subject but you should consider parking on blocks when in storage.

I cut mine from treated 2” X 10” treated wood. We used them on all four trailer wheel positions wherever were parked. I get all of my wood from new home construction sites. I just ask the site foreman. Usually they say anything that has been cut and discarded is free. I cut a 45 degree bevel on one end so as not to be driving up on a sharp edge.

Storage_-_2010_2_ - iRV2.com RV Photo Gallery

[TitanMike]

Originally Posted by mxtreme30

I guess it's apparent I know nothing about trailer axles!
Stopped over at E-trailer website and by George all their axles were bent and the description is exactly as you posted.
To me making the axles this way makes it hard to determine if some nimrod jacked his trailer up from the middle of the axle tube, but hey, what can ya' do. Lol.

And for the OP, don't listen to me. Listen to Mike. I'll just stand over here in left field chasing butterflies!

Sorry for the mis-info.

My advantage, and sometimes a disadvantage, is that I started worked for a company that built Wheel Alignment machinery for 15 years. I lived, ate, and drank, alignment machines, alignment geometry, tire wear, steering issues, on everything from VW Beetles to Kenworth/Peterbuilt trucks (both built by PACCAR). The disadvantage was it often put me at odds with "Old-Timers" who often had their own ideas of steering geometry and how to take accurate measurements.

Overall let's just say it was a "rewarding" ($$$) period in my Career.

On the idea of replaceable spindles on TT Axles, i think it would be a vast improvement. A simple spindle attached to a flange plate welded to the end of the axle. Would allow the installation of tapered shims to adjust camber AND toe quite simply for the absolute maximum tire mileage.

The question is, would manufacturers be willing to buy axles built like that and Customers in turn want to pay extra?

[TitanMike]

Originally Posted by nutdriver

Thanks for the helpful post. I am curious if you have any experience with the Lippert Correct Track system.

The Lippert Correct Track System is a great system for trailers that have a tracking issue with the axles. It's a variation of a system first introduced to make early McPherson Strut equipped vehicle's front suspension "Adjustable".

It utilizes a cam-bolt that was originally designed for vehicles like the Mercury Capri and others that had no Camber Adjustment and eventually showed up on FWD Chryslers, GM products, etc. Kits were sold by companies like Northstar, Specialty Products, and Arn-Wood.

Installing it does require removing old spring bracket and bolting the new bracket in place.

This kit allows for not only correcting track issues but also raises the trailer height (at the axles) by 2"


FWIW, During the development of the M-977 HEMT, I worked with the Engineers at PACCAR test center located a few miles north of where I live now in developing a way to keep all four sets of wheels in alignment, both during manufacture and "in the field" when this truck was being designed for the Army.




Something very similar to the Lippert system, only much heavier duty obviously, was used. Instead of being easily adjustable however the "cams" were just heavy plate washers that had to be moved so alignment was achieved then welded in two places. To "adjust" welds were ground out, moved, and then re-welded.

Compared to these, aligning trailer axles is a piece of cake

[hinkle_e]

Thanks again for all the info. We're done for the season so I'll look into all of this come spring. Definately have a suspension upgrade and tire swap to do though.

[correpat]

We recently had our 2016 MBS 2400 in for service - first time at the MB dealership. Service alert to tighten U-bolt that was not picked up by RV service because they don’t service the chassis. Also, asked for an alignment - whoa! Dealership said they get RVs in all the time because the RV manufacturers change out the single rear axle to a double axle and, to keep costs down, the chassis area NEVER aligned by the chassis manufacturer so we purchase these RVs and trailers without them being aligned. No wonder the tires wear out! Wish they’d just tell you to write the check and take them immediately for an alignment. Tires have started to flatten out and the handling is much better!

[Nastynotchback1]

I had this same issue on a work n play toy hauler. One tire wearing. Bent axle was the cause. Bent right behind the backing plate. Replacement of the axle was the fix.

[2witzmans]

Same dang thing! Every year allienment and 2 new tires. Tired of it. Left rear tire also wearing on outside of tire.

[nutdriver]

Originally Posted by 2witzmans

Same dang thing! Every year allienment and 2 new tires. Tired of it. Left rear tire also wearing on outside of tire.

How are they aligning the to trailer? Are they bending the axle each time?

[2witzmans]

Jeez. I don't know. Didn't think to ask.

[TitanMike]

Originally Posted by 2witzmans

Same dang thing! Every year allienment and 2 new tires. Tired of it. Left rear tire also wearing on outside of tire.

Are you sure you're actually getting an alignment or just a "check".

I would insist on before and after readings of the alignment readings, printed from the alignment machine's computer would be preferable.

Also, look for a shop that can measure all alignment angles in relation to the trailer's centerline. That will take a machine that uses four alignment "Heads" installed on wheels AT THE SAME TIME.

[2witzmans]

Yep, allienment.$230

[extremebike]

I just had the whole running gear changed due to broken leaf and worn out bushings. Also needed new brakes so went with wet bushings.

New was the same price as repair. A no brainer. Tires had wear on inside of left front and outside of left rear. Had to buy one new tire and replaced the other with the spare.

This is on the heavy side of the trailer with the big slide. Now I will have to watch the tire wear and maybe rotate the tires on the one side.

If you have plastic bushings (almost all) then you should have the dealer check.

[TitanMike]

Originally Posted by 2witzmans

Yep, allienment.$230

If you're spending that kind of money on an alignment every year, and it's the same axle, you might consider just replacing the axle. If it doesn't have EZ Lube the axle will cost just over $100. If it has EZ-Lube it'll cost about $70 more.

If you have a jack, a couple jack stands, and some basic hand tools, changing an axle is an "afternoon project".

Something to think about. Check e-trailer for axle prices.