I have 2 tire issues that just surfaced today. Since we have the tire tech folks here see if you can point me in the right direction of the problem. I do not yet have a blow out and I'm trying to keep it that way.
Today I was doing some suspension work and the left rear tire looked very rounded. At 1st I thought it was an illusion. So I went to jack up the camper. I have 4 jack stands and I mark them so they are all extended the same height and I have used them on this setting many times. The left rear tire will not clear the concrete on this setting. It drags real hard. H'mm OK raised all the stands up 1 click (about 1")
Then I put a straight edge across the tire and looked at it. See here
The left rear tire on the TT and at the 3:00 position. Looks rounded and high in the center.
So I went to the 3:00 position between the front and rear. Not as bad here but still has some round to it.
Then to compare it to the left front tire that seemed OK otherwise.
It was not a conclusive check on the camper so I did some more looking on the ground.
The left rear tire with a square up to it. On one end.
Then tried to measure off the first tread. It is about 1/8"
Then went 180 degrees to the other side. This side looks more round.
And measures closer to 3/16"
So I compared this to the left front tire. This one seems to have more round on the ground then I saw on the trailer. But was about 1/8". Sorry for the fuzzy pic. It is hard to show the round.
Then I did the tell all. I measured the OD of the tire of all 4 of them.
I have 3 tires that have a OD circumference of 90".
Then I have this left rear tire at 91". It is bulging in the center more then the other 3. It may not be 360 degrees around as bad. Hard to tell. I have a pi tape at work I can get this to thousands if needed but the tape measure found the 1" difference.
I am suspecting something let loose inside this tire and it needs to go before I end up with a blow out.
Here is some info on this setup.
- Axle weight scaled at 7,660# with no water. When I fill the fresh tank over the front axle it adds 266 # more axle load.
- I have 6,000# axle tubes and 5,000# springs. TT is 10,000# GVWR
- Tires are ST225/75R15 Load range D - Denman Express radials made in Mexico.
- Tire pressure is 65psi. Check at the start of every trip religiously.
- LRD tires have 2,540# load at 65 psi. X 4 tires = 10,160# of tires agasint a scaled axle weight of 7,926#. Or 2,234# of reserve capacity.
- I only tow up to 60 mph. The only time this rig has hit 68 to 70 was passing a semi on very rare occasion. This is approx 2 minutes worth and may only have been 3 to 5 times in the life of this tire.
- Tire DOT date is 2908. Tires installed 3-28-09
- Tire has slightly less then 11,000 miles on it. I can get the exact if needed. Log book is out in the truck.
- I have weighed the left and right side of the camper. The slide side (left) is approx 350 # heavier.
- Trailer has shocks on it but only for the last year.
- Tires have balancing beads in them but only for the last year.
- This tire have never been patched or leaked air.
- Axle alignment within Dexter specs when tire installed new.
- Towing has been on the east coast. OH, PA, MI, NY. We do winter camp. Towing has been always above freezing.
- I did slightly compress the side wall about 6 months after it was put on. :M Pulling into the dump station and I just kissed this high up curb. I stopped instantly and backed out of it. This was not a hard hit, but it happened. A slight burnish about 6" long on the side wall. Cannot find it now. Was going 5 to 8 mph at the time. That was approx 8,500 miles ago.
- Tires are cover with white tire covers when stored at home.
- While this rear tire is bulging the others look the same but can see some level of slightly round to them. Do not know if this is normal or not. Hoping the other are not progressing to this.
- This is what they looked like new. Yes I was tracking the wear with a caliper. This was base line. Had to do with my axle alignment I did.
- Here is a wear check a few months after install. The tire face looks more flat.
OK thoughts? Something is not right with this tire and my gut tells me get ride of it now, put the unused spare (bought same time) on and buy a new tire for the spare. It will be a Maxxis ST as Denman is no longer.
I would like to learn what went wrong or what I did to cause this.
I have my own tire machine and will demount the tire for inside inspection when the new spare comes in.
Thanks
John
I'll post the 2nd question in the next reply. It has to do with cracks in the other tires.
