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Tire/Axle Question

campermama
Explorer II
Explorer II
My travel trailer has Dexter tandem axles. I noticed both tires on the front axle have slight cupping on the outside of the tires.
My fresh water tank is just behind that front axle and over the rear axle.
My question is could having more weight on the rear axle and less on the front axle be causing this?
I don't travel with a full tank but I do have 1/3 - 2/3 filled sometimes since I only boondock.

Everything on or around the axle looks fine otherwise.
2018 Dodge Ram 3500 Laramie,SRW,CTD,4x4,Long bed
2020 Jayco eagle ht 274ckds

My Adventure Blog:
https://roaddivaontheroad.blogspot.com/2020/03/getting-ready.html
15 REPLIES 15

JIMNLIN
Explorer
Explorer
My travel trailer has Dexter tandem axles. I noticed both tires on the front axle have slight cupping on the outside of the tires.

Cupping on the tires outside/same axle on a trailer as others/Jbarca have said is most likely a toe/camber issue (bent axle) and easily fixed by a big rig trailer repair shop. They can tell you what is causing your tires wear issue.

Cupping across the tread is more indicative of a out of balance tire due to internal issues (partial tread delam/etc).
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers

'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides

RLS7201
Explorer
Explorer
Gdetrailes, stated. "Trailer axle bearings are not "factory sealed permanent bearings" which have no adjustments.. They are indeed "adjustable" and as they wear, they should be checked and adjusted as needed. As they are adjustable, it IS possible that they may have left the factory a bit on the loose side (not correct preload) and OP has put 10K miles on the trailer meaning it may be due to check and adjust the bearing preload."

If a properly adjusted tapered bearing has become loose, is should not be readjusted, as there will be metal missing from the bearing, making it non serviceable.

Richard
95 Bounder 32H F53 460
2013 CRV Toad
2 Segways in Toad
First brake job
1941 Hudson

JBarca
Nomad II
Nomad II
Gdetrailer wrote:


John,

That chart CAME DIRECTLY FROM DEXTERS OWN MANUAL ON TRAILER AXLES.

Dexter builds trailer axles.

Snip..

Don't "shoot the messenger".

Snip..

The manual also has a maintenance schedule chart that gives normal maintenance intervals for the bearings and other items which I suspect you and 99.9% of all trailer owners ignore..

It could also just be lousy tire build, and yes, this happens even to the supposed "best brands".. I had a set of trailer tires cup, replaced the tires, no more cupping..

But what really gets me is when folks start blaming it on "bent axles" or "axles out of alignment" as the very first thing to look at when the very first response is to check the simple things like tires being out of round or way out of balance and even checking the bearings preload settings. All things that do not cost a dime rather than making this an extreme sport of spending money.


GD,

I have no beef with Dexter, I feel they are one of the top axle manufactures in the US trailer world. They have helped me greatly in the past with technical service. My beef, if there is one, is with the RV industry who allows welded on hangers to the frame not adhering to Dexter's recommended spec's. and shipping them. Dexter doesn't mention the screwup's the RV industry does to their products. There chart assumes the axles are installed correctly.

The original poster stated their tires are cupping. Do you have any evidence in what they have presented to date they understand what true cupping is? They may have picked a word they heard and thought it was the right one to use.

You picked my post to comment on that cupping can come from an out of balance or wheel bearing issue. And then you get into someone trying to explain about wheel alignment.

I was trying to help them understand that tire wear on a travel trailers comes from many different places, and we need more info to help them better understand what could be going on.

To your statement in blue on what you "suspect" I know or do with campers, don't go there. Leave it alone, you have no idea what I have done and can do in my shop.

And for the record, once we know more about the original posters tire wear, using a standard tape measure with some guidance, they can do some quick measurements across their tires so see if gross wheel alignment exists that can cause tire wear. Then they can figure out if they have the ability to correct the problem or need to find a shop who can. And yes, they can jack up the camper if they can, and feel for bearing wobble or do a tire spin test to look for an out of round conditions. It takes more work jacking up the camper then the tape measure checks. One just needs to understand what to look for when gross wheel alignment exists. And some of us are glad to help them with on how to do it.
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Gdetrailer
Explorer III
Explorer III
JBarca wrote:


The chart shown above is a text book standard chart for tire wear. I do not disagree with any of it. However in this case, we are talking about a travel trailer made in the RV industry, not a car, truck etc. where that chart actually fits better. A tandem axle trailer made in the RV industry with no steering on the lowest budget that just gets by, is very different then an automobile with very good and stable suspension.

I do agree 110% with the statement about once a tire starts wearing bad, it will continue to wear that bad even after the problem is corrected. My step dad was in the garage business for over 40 years working on autos, and I can still hear him telling me that fact, that the tire wear will continue even if the issue was corrected.

Before we start telling Campermama that their wheel bearings are shot or set wrong causing the tire wear they are seeing, it might be better to first confirm that actual cupping as shown in that chart is root cause of the wear on the tires. There was going to be pictures posted so we can see what they are seeing. That can then help a lot better then speculating that cupping is actually happening. Maybe Campermama misdiagnosed the wear and called it cupping, now folks are telling them to fix cupping, fix the tire balance and wheel bearings.

I have measured axle alignment on several campers, corrected bent axle tubes, repaired incorrect hanger locations, and worn suspension to name a few of the issues creating tire wear on a travel trailer. While I have not done thousands of campers on alignment checks, out of all of the ones I did do, none of those tire wear issues were due to actual cupping of a tire due to a wheel bearing going bad or the tire being out of balance. I'm not saying those conditions cannot exist, but I would say it is highly unlikely given what we know so far.

The statement of, an out of balance tire issue causing tire cupping wear on a TT, let's think about that for a moment. Think about how many thousands of travel trailers and 5th wheels leave the factory every day with unbalanced brake drums and tires. Do they all have tire cupping?

If the wheel bearings where set wrong, having excess play, and there is 10K miles on the camper, odds are high, those bearings for 10K miles would be severally damaged to the point of total failure or close to it. Has anyone ever seen a documented trailer wheel bearing survive a bad setup that long?

And then what are the odds that bad bearings and out of balance wheels so bad to cause cupping, just happened to end up on the same axle tube, yet the axle tube next to it, does not have the issue?

With what little we know about this camper wheel alignment, actual tire cupping does not stand out as the root cause of the tire wear. If we can get some pics of all 4 tires, that may help a lot better then assuming cupping is the root cause.

Hope this helps

John


John,

That chart CAME DIRECTLY FROM DEXTERS OWN MANUAL ON TRAILER AXLES.

Dexter builds trailer axles.

Dexter has plenty of paid "engineers" on staff.

Those "Engineers" most likely know more about trailer axles and tire wear on trailer axles than you or I.

Don't "shoot the messenger".

For the record, neither I OR Dexters manual stated anything about REPLACING BEARINGS..

Dexters manual mentioned bearing ADJUSTMENT which if for any reason the bearings are slightly too loose than allowable preload will allow the hub/wheel to wobble enough to cut in "cups".

Trailer axle bearings are not "factory sealed permanent bearings" which have no adjustments.. They are indeed "adjustable" and as they wear, they should be checked and adjusted as needed. As they are adjustable, it IS possible that they may have left the factory a bit on the loose side (not correct preload) and OP has put 10K miles on the trailer meaning it may be due to check and adjust the bearing preload.

The manual outlines the correct instructions for setting the bearing preload..

The manual also has a maintenance schedule chart that gives normal maintenance intervals for the bearings and other items which I suspect you and 99.9% of all trailer owners ignore..

It could also just be lousy tire build, and yes, this happens even to the supposed "best brands".. I had a set of trailer tires cup, replaced the tires, no more cupping..

But what really gets me is when folks start blaming it on "bent axles" or "axles out of alignment" as the very first thing to look at when the very first response is to check the simple things like tires being out of round or way out of balance and even checking the bearings preload settings. All things that do not cost a dime rather than making this an extreme sport of spending money.

JBarca
Nomad II
Nomad II
Gdetrailer wrote:


Annd HERE is what Dexter says..

Page 77..


Click For Full-Size Image.

Snip...

Cupping can come from an out of balance issue or wheel bearing adjustment issue according to Dexter axles manual.


My tire shop tells me once they start wearing odd, nothing can slow it down or fix it other than replacing..


The chart shown above is a text book standard chart for tire wear. I do not disagree with any of it. However in this case, we are talking about a travel trailer made in the RV industry, not a car, truck etc. where that chart actually fits better. A tandem axle trailer made in the RV industry with no steering on the lowest budget that just gets by, is very different then an automobile with very good and stable suspension.

I do agree 110% with the statement about once a tire starts wearing bad, it will continue to wear that bad even after the problem is corrected. My step dad was in the garage business for over 40 years working on autos, and I can still hear him telling me that fact, that the tire wear will continue even if the issue was corrected.

Before we start telling Campermama that their wheel bearings are shot or set wrong causing the tire wear they are seeing, it might be better to first confirm that actual cupping as shown in that chart is root cause of the wear on the tires. There was going to be pictures posted so we can see what they are seeing. That can then help a lot better then speculating that cupping is actually happening. Maybe Campermama misdiagnosed the wear and called it cupping, now folks are telling them to fix cupping, fix the tire balance and wheel bearings.

I have measured axle alignment on several campers, corrected bent axle tubes, repaired incorrect hanger locations, and worn suspension to name a few of the issues creating tire wear on a travel trailer. While I have not done thousands of campers on alignment checks, out of all of the ones I did do, none of those tire wear issues were due to actual cupping of a tire due to a wheel bearing going bad or the tire being out of balance. I'm not saying those conditions cannot exist, but I would say it is highly unlikely given what we know so far.

The statement of, an out of balance tire issue causing tire cupping wear on a TT, let's think about that for a moment. Think about how many thousands of travel trailers and 5th wheels leave the factory every day with unbalanced brake drums and tires. Do they all have tire cupping?

If the wheel bearings where set wrong, having excess play, and there is 10K miles on the camper, odds are high, those bearings for 10K miles would be severally damaged to the point of total failure or close to it. Has anyone ever seen a documented trailer wheel bearing survive a bad setup that long?

And then what are the odds that bad bearings and out of balance wheels so bad to cause cupping, just happened to end up on the same axle tube, yet the axle tube next to it, does not have the issue?

With what little we know about this camper wheel alignment, actual tire cupping does not stand out as the root cause of the tire wear. If we can get some pics of all 4 tires, that may help a lot better then assuming cupping is the root cause.

Hope this helps

John
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Mike134
Explorer
Explorer
as others have said cupping is from out-of-balance.

Yet keyboard warriors who don't have a clue will say that you don't need to balance a rotating wheel.
2019 F150 4X4 1903 payload
2018 Adventurer 21RBS 7700 GVWR.

time2roll
Nomad
Nomad
Outside wear is generally positive camber or toe-in out of spec.
Cupping is usually balance or bad shocks.

Usually overload will cause negative camber so I doubt the water tank is an issue. Axle could have been bent if someone jacked on the axle tube in the middle section at some point. This would cause positive camber. Road hazard would not likely cause this except maybe going up a curb etc. at an odd angle to bend something.

Some truck/trailer places can bend the axle to realign. Otherwise you are looking at replacement.

Yes could be a bad tire but odd to be both on same axle. Tread separating or belt shifting can do lots of odd stuff.

Gdetrailer
Explorer III
Explorer III
campermama wrote:
JBarca wrote:
campermama wrote:
My travel trailer has Dexter tandem axles. I noticed both tires on the front axle have slight cupping on the outside of the tires.
My fresh water tank is just behind that front axle and over the rear axle.
My question is could having more weight on the rear axle and less on the front axle be causing this?
I don't travel with a full tank but I do have 1/3 - 2/3 filled sometimes since I only boondock.

Everything on or around the axle looks fine otherwise.


The added weight of fresh water normally does not create outside tire wear, but axle or wheel alignment can. A pure weight overload more often points to inside tire wear due to loss of correct wheel camber assuming nothing else is messed up.

It would help to know a few things to better understand your tire wear. Here are a few items.

1. How old is the camper?
2. How many approx. miles are on the tires with the wear you now have since the tires were new? (if you know, or how many miles have you put on if you bought the camper used?)

3. Does the camper have leaf spring axles or a torsion axles?

4. Can you post some pics of the thread wear across the face of the tire in clear focus and lighting on all 4 tires? And which pic goes with which wheel location for front or rear tire and left or right tire. And yes, the rear tires help add to the story even if the wear is not as gross amount like the front.

Tire wear (assuming the the tires have not being rotated since new) help tell a story on wheel alignment.

Trailer running gear alignment issues comes from many places. Starting with the hangers welded on wrong on day 1 from the factory, axles being made wrong, worn suspension parts, loose wheel bearings, overloading of the axles, and wheel alignment damage from hitting curbs, pot holes or any other kind of bump at speed to name a few of the common issues.

Sadly, tire wear on campers is common when the wheel alignment is out of tolerance. And it happens somewhat frequently. When the wheels are in proper alignment and the axles not in overload, you will get even wear on the tire face for the life of the tire, other then minor normal outside tire turning wear which is not cupping. When they are out of alignment, the tires scrub the road wearing wrong rather then roll straight ahead.

Hope this helps,

John

PS. There are ways to correct the problems, but it helps first to know what the issue may be to tell you what to correct short of a quick answer, just take it to a RV dealer and let them deal with it. Not all RV dealers can handle trailer axle alignment, the shop needs to know and have the equipment for measuring all aspects of wheel alignment and later correcting the root cause of what is wrong.



I am not talking about it being overweight. I'm saying ALL the weight of the fresh water tank is on the REAR axle. So I am wondering if the FRONT axle with the cupping tire wear, doesn't have enough weight on it??

The trailer is a 2020, I bought it new. Tires are goodyear endurance, probably have about 10k miles on them. Trailer has leaf springs.Just noticed the cupping after the last 2k trip in which I carried more fresh water than usual. The "issue" is only on the front axle tires. Rear axle tires are fine! I'll try to get pictures today.


Annd HERE is what Dexter says..

Page 77..


Click For Full-Size Image.

Cupping can come from an out of balance issue or wheel bearing adjustment issue according to Dexter axles manual.

I have seen tires just suddenly start wearing unevenly for no reason at all as they get some miles on them.

This spring had rear set of tires on my TT start wearing the outside edges quickly (about 300 miles into a 2K mile round trip was down to the wear bars), never had that happen before, loaded the same way as past so no change there, same tow vehicle with same setup no change there.. Only can assume that the tires were just simply done and needed replaced. The replacements have nearly 1K miles on them and look OK..

Had a tire that broke a belt on my other trailer a few yrs back, caused a bulge in the tread area, tire was only 2 yrs old and less than 2K miles on it.

My tire shop tells me once they start wearing odd, nothing can slow it down or fix it other than replacing..

JBarca
Nomad II
Nomad II
campermama wrote:


I am not talking about it being overweight. I'm saying ALL the weight of the fresh water tank is on the REAR axle. So I am wondering if the FRONT axle with the cupping tire wear, doesn't have enough weight on it??

The trailer is a 2020, I bought it new. Tires are goodyear endurance, probably have about 10k miles on them. Trailer has leaf springs.Just noticed the cupping after the last 2k trip in which I carried more fresh water than usual. The "issue" is only on the front axle tires. Rear axle tires are fine! I'll try to get pictures today.


OK, this helps as a start. 10K miles is plenty enough for tire wear to rears it head of an out of alignment issue. Tire wear is slow and you may not notice it at first until it makes it to the obvious looking stage. For heavy outside cupping wear to occur in only 2K miles, that points to a major gross alignment issue, you may have not known the wear started long ago, it started slow until it wore enough it becomes more obvious. This is common to show up this way.

The weight of the fresh tank being over the front or rear axle "normally" should not cause cupping on the opposite axle. The steel trailer frame and the way the suspension is made helps to spread the load out over both. While both axle loads may not be exactly the same and normally are not, adding water to the fresh tank should not be a factor for cupping on the outside of the tire, assuming you have a semi normal size fresh tank.

In the event you have something special, what make/model camper and what size (gallons) is the fresh tank?

Cupping on the outside of the tire often comes from 2 areas, excessive toe wheel alignment out of spec, or the thrust angle of the front axle is not correct to the tow ball allowing the trailer to dog track off center when it gets bad enough. But tires will wear if the thrust angle is off even if the toe angle is correct.

To what the other poster asked, how is the towing stance of the camper when going down the road, nose high, level or nose low? If nose high or low, how high or low at the tow ball in approx. inches.

Hope this helps

John
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

enblethen
Nomad
Nomad
Is the trailer sitting level or close to it when ready to hit the road?

Bud
USAF Retired
Pace Arrow


2003 Chev Ice Road Tracker

campermama
Explorer II
Explorer II
JBarca wrote:
campermama wrote:
My travel trailer has Dexter tandem axles. I noticed both tires on the front axle have slight cupping on the outside of the tires.
My fresh water tank is just behind that front axle and over the rear axle.
My question is could having more weight on the rear axle and less on the front axle be causing this?
I don't travel with a full tank but I do have 1/3 - 2/3 filled sometimes since I only boondock.

Everything on or around the axle looks fine otherwise.


The added weight of fresh water normally does not create outside tire wear, but axle or wheel alignment can. A pure weight overload more often points to inside tire wear due to loss of correct wheel camber assuming nothing else is messed up.

It would help to know a few things to better understand your tire wear. Here are a few items.

1. How old is the camper?
2. How many approx. miles are on the tires with the wear you now have since the tires were new? (if you know, or how many miles have you put on if you bought the camper used?)

3. Does the camper have leaf spring axles or a torsion axles?

4. Can you post some pics of the thread wear across the face of the tire in clear focus and lighting on all 4 tires? And which pic goes with which wheel location for front or rear tire and left or right tire. And yes, the rear tires help add to the story even if the wear is not as gross amount like the front.

Tire wear (assuming the the tires have not being rotated since new) help tell a story on wheel alignment.

Trailer running gear alignment issues comes from many places. Starting with the hangers welded on wrong on day 1 from the factory, axles being made wrong, worn suspension parts, loose wheel bearings, overloading of the axles, and wheel alignment damage from hitting curbs, pot holes or any other kind of bump at speed to name a few of the common issues.

Sadly, tire wear on campers is common when the wheel alignment is out of tolerance. And it happens somewhat frequently. When the wheels are in proper alignment and the axles not in overload, you will get even wear on the tire face for the life of the tire, other then minor normal outside tire turning wear which is not cupping. When they are out of alignment, the tires scrub the road wearing wrong rather then roll straight ahead.

Hope this helps,

John

PS. There are ways to correct the problems, but it helps first to know what the issue may be to tell you what to correct short of a quick answer, just take it to a RV dealer and let them deal with it. Not all RV dealers can handle trailer axle alignment, the shop needs to know and have the equipment for measuring all aspects of wheel alignment and later correcting the root cause of what is wrong.



I am not talking about it being overweight. I'm saying ALL the weight of the fresh water tank is on the REAR axle. So I am wondering if the FRONT axle with the cupping tire wear, doesn't have enough weight on it??

The trailer is a 2020, I bought it new. Tires are goodyear endurance, probably have about 10k miles on them. Trailer has leaf springs.Just noticed the cupping after the last 2k trip in which I carried more fresh water than usual. The "issue" is only on the front axle tires. Rear axle tires are fine! I'll try to get pictures today.
2018 Dodge Ram 3500 Laramie,SRW,CTD,4x4,Long bed
2020 Jayco eagle ht 274ckds

My Adventure Blog:
https://roaddivaontheroad.blogspot.com/2020/03/getting-ready.html

JBarca
Nomad II
Nomad II
campermama wrote:
My travel trailer has Dexter tandem axles. I noticed both tires on the front axle have slight cupping on the outside of the tires.
My fresh water tank is just behind that front axle and over the rear axle.
My question is could having more weight on the rear axle and less on the front axle be causing this?
I don't travel with a full tank but I do have 1/3 - 2/3 filled sometimes since I only boondock.

Everything on or around the axle looks fine otherwise.


The added weight of fresh water normally does not create outside tire wear, but axle or wheel alignment can. A pure weight overload more often points to inside tire wear due to loss of correct wheel camber assuming nothing else is messed up.

It would help to know a few things to better understand your tire wear. Here are a few items.

1. How old is the camper?
2. How many approx. miles are on the tires with the wear you now have since the tires were new? (if you know, or how many miles have you put on if you bought the camper used?)

3. Does the camper have leaf spring axles or a torsion axles?

4. Can you post some pics of the thread wear across the face of the tire in clear focus and lighting on all 4 tires? And which pic goes with which wheel location for front or rear tire and left or right tire. And yes, the rear tires help add to the story even if the wear is not as gross amount like the front.

Tire wear (assuming the the tires have not being rotated since new) help tell a story on wheel alignment.

Trailer running gear alignment issues comes from many places. Starting with the hangers welded on wrong on day 1 from the factory, axles being made wrong, worn suspension parts, loose wheel bearings, overloading of the axles, and wheel alignment damage from hitting curbs, pot holes or any other kind of bump at speed to name a few of the common issues.

Sadly, tire wear on campers is common when the wheel alignment is out of tolerance. And it happens somewhat frequently. When the wheels are in proper alignment and the axles not in overload, you will get even wear on the tire face for the life of the tire, other then minor normal outside tire turning wear which is not cupping. When they are out of alignment, the tires scrub the road wearing wrong rather then roll straight ahead.

Hope this helps,

John

PS. There are ways to correct the problems, but it helps first to know what the issue may be to tell you what to correct short of a quick answer, just take it to a RV dealer and let them deal with it. Not all RV dealers can handle trailer axle alignment, the shop needs to know and have the equipment for measuring all aspects of wheel alignment and later correcting the root cause of what is wrong.
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Grit_dog
Nomad III
Nomad III
campermama wrote:
My travel trailer has Dexter tandem axles. I noticed both tires on the front axle have slight cupping on the outside of the tires.
My fresh water tank is just behind that front axle and over the rear axle.
My question is could having more weight on the rear axle and less on the front axle be causing this?


Nope.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold