OT RV always the inner dual...

Why is it always the inner dual on the RV that goes? 225 75 r16s Load range E is it because I bought Mastercraft? The Coopers did the same thing. Invested in Generals for the front when the last Mastercraft slipped a belt and egged out on me.

Its a 35 class C Ford chassis V10, I love it but every 3 years (only put 3000 miles on it) I end up changing tires on the side of the road. Yesterday I got that inner dual (passenger side) switched out in about 17 minutes.

Is this normal or is something up?

GREAT QUESTION Ive owned RV;s for fifty years,,,,,,,,,A ton of Class C's (I'm a user plus a past used dealer) ,,,,,,,,,,,Experienced
blowouts OFTEN THE PASSENGER SIDE INSIDE DUAL

Its MY OPINION so often a blow out is due to under inflation which increases heat due to friction so KEEP TIRES AIRED UP and at each gas
stop use a temp gun to find over hot tires and/or perhaps a hot wheel due to a dragging hanging caliper..


Here's MY OPINION of why the passenger side inside dual is often the one that blows out

1) Due to the ever slight crown on the road its THE INSIDE rear dual that carries more weight (causing more heat and more PSI) versus the
outer........

2) Often the inner dual is closer to the heat of an exhaust pipe

3) The inner dual runs hotter then the outer due to less cooling air flow past it

4) If the inner dual runs hotter it increases air pressure more then the outer thereby a tad bigger diameter thereby carrying more weight
then the cooler outer dual

Heres what I do that may help

1) I run about 4/5 more PSI in the outer then the inner dual

2) I believe theres a chance that will even out the load each carries for the reasons above

3) I when cool air my tires to the MAX LOAD AT X PSI on the tires sidewall (but outer left dual 4/5 more) and NOT less to give me a softer
ride. My Load Range E 10 Ply rated LT 225 75 x R16 on my Class C call for Max Load at 83 PSI

NOTE when shopping for tires in my size I found Michelin and Firestone had a max load rating around 2500 Lbs but Continental Vanco Four
Season were 3195 SO THATS WHAT I BOUGHT and even if tread is fine I change out at five to no more then seven years

NOTE Im NOT a tire expert or a mechanical engineer but a Lay Person (owned RV and trucks of all kinds over fifty years) and this IS ONLY
MY OPINION which others may disagree with and/or have other theories which is fine and welcome TO EACH THEIR OWN OPINIONS Lets get along
and help each other, NOT fight, best we can and figure out why its often the passenger inner dual that blows ?????????? Love to hear other
reasons and love to hear from professional experienced tire experts and other lay gents like myself

Best wishes everyone, be safe and God Bless yall and God Bless America

John T One happy and contented camper

Those are good observations. I will add that the inner dual is more aligned with the front tires which can setup nails and foreign objects to be poked into the inner dual. The dual gets under inflated causing heating and fails The failure may not be blamed on the Puncture. Jim

Inner dual gets to carry all of the weight any time
you drive a bit too close to the edge of the
pavement. Truck drivers will tell you this as will the
road side tire repair guys. The more experienced a
driver is , the less likely this will happen. If you dont
drive your RV far or often, then you are probably
trying to be very careful driving this large vehicle,
and cautions about sharing the road. I see RVs
hitting the gravel frequently, but you dont see that
happening with large trucks as much.

Trivia ... Mastercraft tires are made by
Cooper. I have Mastercraft tires on my
pickup purchased at a Cooper dealer,
that's what they said. They sell them at
a lower price than Cooper. So far they've
worked well for me. Also Cooper was
recently acquired by Goodyear.

The tire is overloaded because of most of the reasons John stated. The inside dual can't cool as well and in addition the heat from the hub is greater on the inside. The inside dual might be within the load rating stamped on the sidewall but the additional heat from where it is located lowers the acceptable load rating. A 3200 pound rated tire might hold up under only lets say 2500 pounds if it is located where it cannot cool efficiently. On very hot days we used to throw caps off of tires on dual wheel tandem axle trailers that were bumping the limit of the rated load range. A third axle was added to the trailers and throwing caps pretty much went away. Other weird tire wear problems started appearing but that could be solved by changing tires before the disaster hit. The tire problem was mainly on the ditch side because the high center of gravity of the load made the trailer lean toward the ditch. A higher ply tire does not always solve the problem because the thicker tire can't dissipate heat as well.

On my service truck. It was always the inner tire. 105 or 20 with wind.

We had the same problem with grain trucks. The axle bends a little bit when you are loaded, on top of all the other factors.

Making the inner dual carry even MORE weight and run hotter grrrrrrrrrr

John T

On our motor home it was always the
inside tire. I thought it was under the
closet where wife filled.

Having the tire rotated each year might help.

Are you driving with the right side loaded heavier? Maybe a full water tank or more cargo on the right side.

Thanks gang, I appreciate the insights. I think Ill run the outside +4 or 5 and see what happens.

Years past when changing the inner, I would switch the worn outer to the inside and put the new spare on the outside. Next tire to go was that old outer on the inside. A buddy and I hypothesized that the plys let loose as it was worn in running a few thousand miles turning in the opposite direction.

Yesterdays spare went onto the inside.

Determined, it sits level and the waste water tanks are on the drivers side.
I have not weighed it much-less checked the balance.

Trips to Yellowstone (from Ohio, 3000+ miles each trip) I would lose the drivers side inner too.

I never had time or money to change the tires before a trip, but ON the trip the wife was ok with 1 or 2 replacements...

Doesn't matter if it is an RV or a 6 whee truck or 10 wheel the inner dual always seems to be the one that goes flat

The inner tire gets more of the heat from the brakes...and less of the wind draft to cool them..

Get a TPMS system. Tired monitoring.
Keeps track of tire pressure and
temperature real time.

Everybody has some really good points on this . Being a certified master tech on cars and trucks of the past and also being a truck driver and owner operator over the years along with managing the mobile equipment end of two different oil filed operations i have seen lots of tire failures . I have probable hauled a lot heavier loads then most on here long distances up to a quarter million pound . Yep the crown of the road has and affect on tire ware the outside drivers side will ware more the the outside passenger side . Axle alignment on trailers has a strong affect same as on any truck , if the axle on the rear is running out just a 1/16 of and inch you will probable never notice it , This can be caused by loose u/bolts on the axle and allow it to shift due to torque of the drive , so this is something to look at and have checked by someone who knows what they are doing , you can get a rough guesstamation with a tape measure and the help of a friend off the center point up in the ft of the vehicle and measure back to the rear axle near each side of the springs . Next is your tire gauge , just how accurate is it ????? They are NOT all dead Nuts on as my one friend found out His three gauges he had were way off one read low one read high and the other was only eight pounds off . Everybody thinks that there gauge is dead on --------- Are you sure , best check . I am lucky in this dept. as just a little over two miles south of me is Haltec they make and sell stuff for the tire industry . I stopped there to get tire gauges and Mr. Hall took me back and hand picked five gauges out of the one tote and took them over to the test bench where they test each one and out of the five one did not read dead on and got tossed into the reject bin and he tested another . He told me that his are good BUT they do NOT LAST FOR EVER and shame on you if you sure a standard gauge to check a loaded of past loaded tractor tire unless it has a new unloaded tube as the Cal . will mess them up . Each of my vehicles has a gauge in the glove box and i carry one gauge that was made for the Cal filled tractor tires in my service truck . During my shell we say OUTLAW trucking days of pulling coal bucket and hauling 40-45 ton each load on just FIVE axles and NOT just short hops the org. tires that came on my new East dump trailer did not last two weeks and in two weeks i ate 16 tires . I upgraded from a what was called the GOODYEAR CARGO High miler to a second line Good Year Steering tire and plum wore them out and never popped one , few flats here and there due to hauling in and out of scrap yards. And other trick on tire pressure is checking air pressure when the tires are COOL and NOT one side setting in the sun and the other side in the shade that can cause one side to read high while the other side is either low or dead on the money . Never put the gauge to a tire that is hot from running as you will get a false reading . I ran 85 PSI on my old 10x22 tube tires on the semi and hauled those loads at that pressure , The side wall instructions for them were 85 max for single operation and and 75 for dual operation BUT add 10 PSI for speeds over 65 so the steering was set at 95 and the dual at 85 . A lot of my fellow bucket haulers all said run 110 i had less tire problems at the 85 and hauled as heavy and at times more . On my Dodge one ton service truck and as she sets with all the tools and equipment she is just about 10500 and sets on 235-85 16 E rating Coursers the ft axle is at 85 PSI and the duals are at 75 , now granted i don't do much driving with it as a 95 with 157 and change on the clock but when i went to Mo. i had all the tires set a 85 and i was a WEEEEEEE bit over the 11000 GVW and only stopped once in 627.4 miles and that was to grab a bit to eat and check tires and it was in the 90's that day and all were cool. So check your alignment and your tire gauges .

Lot of real good thoughts and ideas on here, I like the thought of carrying more in the outside tires. We have a TPMS system and I really like it. Next time we're out I'll try to remember to look at how much the inside tire pressure increases compared to the outside tires. Our TPMS system also displays temperature but I don't put much stock in that as it's just the temperature of the sensor screwed on the valve stem, but it also would be worth noting the temperatures just the same. We have a Class A gas burner and we tow a 1991 Jeep Wrangler. I like the TPMS system as much as anything for the Jeep. If one of the tires on the Jeep failed we may never feel it driving the coach. Now if it was night time we might see a shower of sparks from the hub dragging the road. . We have a 10 sensor system, six on the coach, four on the jeep and you can program different alarm points on the two vehicles. It would be kind of neat if a person could add extra sensors without alarms to monitor the spare tire and maybe even the pressure in the air boost spring as well. I figure the cost of couple tires is about what the system cost.

Farm truck lugs can get awfully rusty by the time you need to take off that inner dual.

Indeed, been there done that grrrrrrrrrrrrr had to use a decent size cheater bar

John T

"Inner dual gets to carry all[/u:df662c620a] of the weight any time you drive a bit too close to the edge of the pavement. I was in the truck. Off edge , inside blew, next all weight to outer & it blew. Way overload though.

I'm going with the tires are not big enough for the load. Like wagons on those flimsy 9.35L 15s or 11L15s then with truck tires on the same load the 20's seem to carry it just fine with no problems. On the truck I didn't have trouble with blow outs just would wear the tread off if the tires were not very close to the same tread depth. Another words if you put a new tire against a half worn tire the more worn tire scuffs off the tread as it is trying to keep up with the new deeper tread tire that is rolling along. Saw it real bad on the trailer with those 255R 7022.5 tires. The short one would wear out faster. I got so I relaced them in pairs then saved the best one to match up with a used one from home later to finish wearing out . This helped a lot of tire life. Drive tires which were 11R 24.5's didn't seem to show that problem so much. I suppose it was because of the driving of the wheel from the axle.

The number one cause of 'blowouts' is underinflation. There are TPMS kits available today for a little more than the cost of a single tire; seems like a good investment for any vehicle with duals.
Six sensor TPMS 300 bucks