15" ST Failure to 16" Replacement..a journey

[jcanavera]

I have a tire problem that seems to defy my understanding and hopefully some of you might have some ideas.


We went out on our first campout of the year last week. My tires are into their 4th season. Prior to pulling out of the garage, I checked the pressures on each tire and brought them up to 80 psi, which is the max for my E rated tires. We pulled an especially heavy load with full fresh water tanks. I was probably grossing at around 8,900-9,000 lbs. Our trip was about 220 miles one way. The trip up was uneventful and upon arrival I put my tandem axle wheel lock between the tires on the curb side.

Water tanks were empty and much of the extra food we had brought had been eaten so my estimate was the trailer was most likely 500+ lbs lighter for the return home. On arriving home I backed the trailer into the drive. I sometimes have to do a hard pivot to get the trailer into the drive (dependent upon street parked cars). I got the trailer straight in the drive although it had to pivot the last 3 or so feet. Sometimes I pull forward and back a second time to refine the angle of the trailer and to get the tires out of the pivot mode. On this day I did not. I got out of the trailer and attempted to put the wheel lock between the tandem axles on the street side. I noted that the street side front tire showed some deflection and the wheel lock would not open up into a locked position due to the space between the tires being smaller. I went over to the curb side and had the same problem. At that point I didn't feel like restarting the van and attempting to take the stress off the front axle tires.

Fast forward to today and I hitched up to take the trailer back to my storage garage. I hitched up and pulled out and got the trailer straight behind the van. I typically get out of the van and rewalk the outside of the trailer, checking everything one last time. I noticed at that point that both tires on the front axle seem to be visibly higher in the center that on the outside tread. Putting my hand across the tread confirmed that the center tread was higher than the side tread. I thought that possibly the tires being left in a pivot mode might have temporary flexed the belts and that it would all straighten itself out after I got the trailer back into storage.

After a 25 mile 50 mph drive, I got the trailer into it's storage area and rechecked the tires. Front axle tires show that the center tread area is higher than the sidewalls. Rear axle tires are flat across the tread.

Obviously something happened and I'm trying to understand if I have broken belts on the front tires. I've never seen a belt broken however that seems to affect the center tread area around the circumference of the tire. Usually a broken belt shows a distention in an area of the tire. I think the fact that my wheel lock problem proves that we weren't dealing with an abnormal wear problem. Yet on the other hand I did not hit anything on the way home that would have damaged both front tires at the same time.

I guess I'm wondering if leaving the tires in stress in a pivot for a week, could have damaged tire belts or could this be a catastrophic belt failure affecting two tires on the same axle at one time?

I didn't have a camera or time to pull the tires, but obviously my confidence in the tires is shaken. I curious if anyone has seen this problem or have this experience.

Jack

[Al - K4GLU]

Jack I'm no expert by a long shot but it sounds to me like you've got tread separation on both of those tires. Why it would happen to both tires on the same axle at the same time I have no clue beyond a possible axle problem. What brand of tire are you using?

[AWCHIEF]

Sounds like your tires are over inflated. What you describe indicates that.

[xrvr]

Maybe there was more weight on the front axle overloading the tires if they were already near replacement time? Jim

[jcanavera]

The tires are Maxxis E rated tires. Max cold inflation is 80 psi, which is my usually inflation pressure when I'm carrying my maximum loads.

I'm lucky that we had no failure on the road. No sign of any breaks in the tires at this point. I'm going to jack up a wheel next weekend and spin the tire to see if it exhibits any sign of distention like a broken belt would exhibit.

Michael, I know we aren't over inflated since I personally checked all 4 tires about 2 weeks ago. No air has been added since. I will also check tire pressure next weekend.

[Friday]

There is a common misconception about max tire pressure... which isn't helped by a lot of RV dealers I've been to. My last trip to the AS dealer, they didn't even check my tires and one was low... I asked for them to fill it up to 40psi for me (max is 50 for my tire) and they said 'We fill everything up to 50'.

Why? They didn't know - they were just told to do it. My 22' tires are rated for 1870lbs at 50psi. My trailer weights < 5000lbs loaded... so I have 2500lbs of excess tire capacity. I've experimented with handling vs. psi and found 40psi gives me a good combination of ride, sway, and I get about a 2psi rise 'hot' vs. 'cold'. Perfect.

Anyway... if they are still round, it's unlikely a belt has cracked or something is separated... those will usually shake themselves to death. It's possible the high inflation and an increase in temperature caused your problem...

Another possibility is when you were parked the axles were not equally loaded, and your one axle was over weight and stressed the tires. Again, if your tires aren't blown up like balloons, it will give the tires a chance to deform (properly) and share the load with the other axle.

When I take my work truck to GM, they always want to load the tires to 80psi... It's a 3/4 ton, yes, but it's empty most of the time... so I run 50 with no problems and a much nicer ride. My coworker who has a Suburban lets them jack his to 80psi... same tires... his truck rides like crap and the front end has been rebuilt once already...

If you have excess load capacity in your tires, I'd try a bit less air... You can check temperature, but psi is a direct relation to temperature... as long as you aren't getting more than a 10% rise cold to hot, you're gold.

[overlander63]

Belts can shift and separate without having bumps or lumps in the tread or sidewall. I replaced a pair of tires on my trailer a couple of months ago that had belt issues. One was bulging all the way around the circumference of the tire, like you described. The other was opposite, all around the outer edge the tread was worn off, but the tire looked round. I took them off the wheels, and both showed signs of belt issues inside. Last year I replaced a tire that had the classic "separation lump" in the tread.

[ZoominC6]

Jack,

Interesting post and I hope by now that you have it worked out. We too have "E" rated with max pressure at 80psi cold on our 30'Classic S/O. I've always inflated mine to 65psi max and note that they heat up into the mid to high 70psi range when traveling. I've had these tires for two years now with no problems like I did with the old Good Years. Mine are Carlisles and I won't go back based on my experience to date. The first thought I had when reading your post was over inflation; however, I'm no tire expert and only know what works and doesn't work on our Airstream. I look forward to reading your follow-up posts regarding your tires.

Dick

[jcanavera]

Thankfully there is a wealth of information in the various tire threads that are on the forums. I went back to a thread started in 2007 that had various pictures of failed tires. One of the pictures was right on the mark in showing a Marathon with the bulging tread in the center of the tire. From that information and additional posts in the same thread, one of which was from a user with the same tires and situation as mine, I think I've determined that I have a case of belt separation going on with the two Maxxis tires on the front axle of the trailer. My last stop was about 60 miles out of St. Louis and I did check the tires at that point at a rest stop and saw no tire abnormalities. My gut feeling is that the belt separation may have occurred during the back in of my trailer to my drive. That is the same place where my previous tire failure occurred on a Marathon (although that tire was missing a piece of tread that I think came off just before getting to my home). I'm wondering if the tires being hot from the run home are more susceptible to belt separation when subject to pivoting on a concrete driveway? I do know that we were in the 90's on the trip home.

At this point I am seriously considering going the LT 16" wheel route. I noticed that Michelin has a $70 rebate going on for a set of 4 tires so that eases the burden somewhat.

Jack

[HowieE]

You have tread separation on those 2 front tires. They will blow in short order.

Also you are more than likely over inflating the tire at 80 lbs. Please check this chart to get an idea of the proper inflation for your load. I run 45 lbs in my 16 Es and a 34 fter. and that is slightly overinflated.
http://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

All tire manufactures have to meet the same standards so the chart is good for your tires also.

[jcanavera]

Howie, thanks for the comments. From what I understand, while I am inflating more than the 65 psi that D rated tire chart shows, my inflation is well within the manufacturers ratings for E rated tires. One of the reason of going with E rated tires was to provide an addition margin of load capacity in regards to my fully loaded trailer and the capacities of the D rated tires. Based on my loads, my old D rated tires had about 10% or so left in reserve. The 30' or 31' Classic slide outs were the heaviest trailers built by Airstream on a tandem axle. Your 34' unit has an additional axle and the load per axle is less.

Even if I am inflated for a higher load than what I'm carrying, the offset should not be tread separation if I'm within the tire manufacturers inflation specs.

Jack

[idroba]

Jack, I think you are probably right that the heat of travel combined with the side ways pressures of backing into your driveway may have caused the separation you seem to have experienced. Dual axle trailers in tight turning situations experience a lot of side pressure scrub as you are essentially pushing the tire sideways at the hub, but holding it firm on the concrete at the tread. I once had a back in situation which was so difficult and unique that I had to remove one set of tires in order to get the trailer into place. Now that was a royal PITA, but it only happened once a year so I could put up with it. The sideways tire scrub made it impossible to put the trailer in the place it had to go with both axles having tires on them.

If you go to the 16" wheels and tires you probably will be better off in the long run, but realize that the twisting forces on the tires will still be there in your back in situation, and no brand of tire is totally immune to failure given stresses it was not designed to take. If it might be heat related, is there any possibility you could cool the tires down with a hose prior to your back in?

BTW, I put 16" wheels and Goodrich LT tires on my single axle Argosy, and so far I am pleased with the overall results. The Goodrich LT 225/75 R 16 tires are another quality match, so you would not have to go with the Michelin if you didn't want. Note that I said Goodrich, not Goodyear....lol.

[darlingbooks]

The problem you have, may just be a characteristic of how the tires wear when in tight turns, due to the pivot point of your trailer.

Our trailer having three axles, and a Hensley hitch, when in tight turns, the pivot point is forward of the center axel, and mostly on the front axel. What happens to our tires in a tight turn is the back two axels tires slide sideways, and the rear tires more harshly. I discovered extreme wear on the rear axels tires, and it was mostly inside edge wear down to the cords. The front tires still had a safe amount of tread.

Your pivot point of your trailer must be more so on the rear axel, and the front tires slide sideways more so in a tight turn, therefore erasing the tread.

Steve

[HowieE]

Originally Posted by darlingbooks

The problem you have, may just be a characteristic of how the tires wear when in tight turns, due to the pivot point of your trailer.

Our trailer having three axles, and a Hensley hitch, when in tight turns, the pivot point is forward of the center axel, and mostly on the front axel. What happens to our tires in a tight turn is the back two axels tires slide sideways, and the rear tires more harshly. I discovered extreme wear on the rear axels tires, and it was mostly inside edge wear down to the cords. The front tires still had a safe amount of tread.

Your pivot point of your trailer must be more so on the rear axel, and the front tires slide sideways more so in a tight turn, therefore erasing the tread.

Steve

If your trailer is riding parallel to the ground the pivot point will be the center axle and you will see deflection in both the front and rear tires while turning. Your description of excessive wear on the inside of one of the tires is an indication of axle misalignment. An easy way to check your axles is to take an 8 ft florescent light bulb and lay it across the center of all 3 tires. The front and rear edge of each tire should be touching the bulb. Any gap to the rear of a tire would cause wear in the inside edge and any gap on the forward edge would cause outside wear.

[jcanavera]

Originally Posted by idroba

J
If you go to the 16" wheels and tires you probably will be better off in the long run, but realize that the twisting forces on the tires will still be there in your back in situation, and no brand of tire is totally immune to failure given stresses it was not designed to take. If it might be heat related, is there any possibility you could cool the tires down with a hose prior to your back in?

It's an interesting option but not always doable since I'm on a cul de sac and we normally get the trailer off the street ASAP since it won't fit at a parking spot on the circle due to other parked cars. Funny though I've had 3 tandem axle trailers prior to the Classic but none quite as heavy and in my last two prior (one a 30' SOB, and a 27' Safari) to the Classic, I traded them in before their tires got past age two. I've had the Classic almost 8 years and the first tire failure (Marathon) came on the final trip of the year as the tires were finishing their 4 travel year. The Maxxis tires have failed now in their 4th year and the first trip of the year.

Jack

[HowieE]

Tires inflated to 80 lbs will run only warm to the touch. If they are running hot I would check the brakes for drag or separation of the tread. Separated tread will run very hot as that is what causes the blowouts.

I do a 90 degree tight turn on pavement in and out of my drive on every trip. The Michelins 16 LTs show almost no wear after 5 years. I can't see any systems of turns in normal driving that would cause notisable tire wear.

I can't see why a HaHa would cause the pivot point to move forward of the center axle on a try axle. While turning I can clearly see opposing deflection in the front and rear axle tires while the center axle is running true.

[MrUKToad]

Originally Posted by Friday

There is a common misconception about max tire pressure... which isn't helped by a lot of RV dealers I've been to. My last trip to the AS dealer, they didn't even check my tires and one was low... I asked for them to fill it up to 40psi for me (max is 50 for my tire) and they said 'We fill everything up to 50'.

Why? They didn't know - they were just told to do it. My 22' tires are rated for 1870lbs at 50psi. My trailer weights < 5000lbs loaded... so I have 2500lbs of excess tire capacity. I've experimented with handling vs. psi and found 40psi gives me a good combination of ride, sway, and I get about a 2psi rise 'hot' vs. 'cold'. Perfect.

Anyway... if they are still round, it's unlikely a belt has cracked or something is separated... those will usually shake themselves to death. It's possible the high inflation and an increase in temperature caused your problem...

Another possibility is when you were parked the axles were not equally loaded, and your one axle was over weight and stressed the tires. Again, if your tires aren't blown up like balloons, it will give the tires a chance to deform (properly) and share the load with the other axle.

When I take my work truck to GM, they always want to load the tires to 80psi... It's a 3/4 ton, yes, but it's empty most of the time... so I run 50 with no problems and a much nicer ride. My coworker who has a Suburban lets them jack his to 80psi... same tires... his truck rides like crap and the front end has been rebuilt once already...

If you have excess load capacity in your tires, I'd try a bit less air... You can check temperature, but psi is a direct relation to temperature... as long as you aren't getting more than a 10% rise cold to hot, you're gold.

In support of Friday's comments, really.

My Airstream was purchased and set up by a well known towing fellow in London, Ontario. He was present when we were doing the handover and the mechanic in the shop was checking the tires. The mechanic said that the tires were at 55 psi but should be 65 psi, the maximum shown on the tire. My towing experting interrupted and said no, 55 psi was correct for normal running. I've subsequently heard him in his talks saying that you shouldn't inflate to the maximum, even when running in very hot weather.

I'm aware that overly flexible side walls can cause overheating but this 10 psi below seems to be an optimum setting, keeping the side walls stiff enough but the tire still flexible enough to absorb some of the lumps and bumps in the road without causing a bounce. Our trip to Florida last year seemed to prove the point as I did monitor the tires' temperature (in a very unscientific manner I will admit) but they were certainly not overheating.

[Phoenix]

There are lots of conflicting opinions regarding proper pressure for trailer tires. Please see below, before deciding for yourself:

Discount Tire: Trailer Tire Facts - Discount Tire

Extracts from above link:

* Underinflation is the number one cause of trailer tire failure.

* Always inflate trailer tires to the maximum inflation indicated on the sidewall.

Costco recommendation is identical.


On our single axle, 19-foot Bambi, we run 80 psi in Michelin XPS Ribs (225/75x16 LT, load range E).

We had Goodyear Marathons (ST, load range D) and Maxxis (ST, load range E) tires both fail (blowouts and tread separation) before switching to Michelins about 1.5 years ago. Absolutely, no problems since then, in about 3-4,000 miles.

[HowieE]

Originally Posted by jcanavera

Howie, thanks for the comments. From what I understand, while I am inflating more than the 65 psi that D rated tire chart shows, my inflation is well within the manufacturers ratings for E rated tires. One of the reason of going with E rated tires was to provide an addition margin of load capacity in regards to my fully loaded trailer and the capacities of the D rated tires. Based on my loads, my old D rated tires had about 10% or so left in reserve. The 30' or 31' Classic slide outs were the heaviest trailers built by Airstream on a tandem axle. Your 34' unit has an additional axle and the load per axle is less.

Even if I am inflated for a higher load than what I'm carrying, the offset should not be tread separation if I'm within the tire manufacturers inflation specs.

Jack

Not sure what you said here. Are you inflating a D rated tire to E pressures? If so Lord knows what problems you could be getting into. If that trailer weighs enough for an E rated tire that is what should be on it. Airstream has a tendency to skate as close to the edge as possible on tires. The bean counters rule.

The recommended tire pressures on the manufactures chart is the tire pressure that will provide the best ride quality and tire wear for that load. Over inflating will result in center tread wear under inflating will result in both edges wearing and if too low blowouts as a result of tread separation .

Tire separations while often a result of under inflation can develop from any number of additional manufacturing flaws.

[HowieE]

Originally Posted by Phoenix

There are lots of conflicting opinions regarding proper pressure for trailer tires. Please see below, before deciding for yourself:

Discount Tire: Trailer Tire Facts - Discount Tire

Extracts from above link:

* Underinflation is the number one cause of trailer tire failure.

* Always inflate trailer tires to the maximum inflation indicated on the sidewall.

Costco recommendation is identical.


On our single axle, 19-foot Bambi, we run 80 psi in Michelin XPS Ribs (225/75x16 LT, load range E).

We had Goodyear Marathons (ST, load range D) and Maxxis (ST, load range E) tires both fail (blowouts and tread separation) before switching to Michelins about 1.5 years ago. Absolutely, no problems since then, in about 3-4,000 miles.

I would hope NO ONE would consider following these recommendation. Looks like American Discount Tire had their lawyer write this. I again suggest using the manufactures inflation charts. If you don't want to do that at least go up to Ontario Canada and have Andy inflate your tires to the right pressure.

It is a shame that Michelin took their inflation chart off the web but if you call them they will give you the recommendations for you load. But as noted above the chart is the same for a given tire type across the board.