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Michelin 315 tag tire issues
A couple years ago, I had a catastrophic failure of a 4 year old Michelin 315 located on the left tag which had been rotated from the left front. I rotated both frt 315’s to the tag and upgraded to 365 fronts.
Yesterday, I noticed what appears to be a sidewall separation on the now 4-5 year old right 315 tag.
WHAT THE HECK IS GOING ON! Is it possible the rotation is causing problems; I did this on my 40′ and had no issues. They’re not overloaded and I know the current tire was never run underinflated. I rarely raise the tag when maneuvering unless it’s really tight. I did switch to 455’s on the drive but weights and diameters are all good. Maybe the 455’s compress more on bumps than two 315’s creating a momentary spike in the weights on the tag tires?
Looking for opinions but at this point I feel I can’t trust 315’s on the tag and I think I’ll go to 365’s.
1999 XLV X-6872, liberty #440 -
26 Replies
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Joel, what pressure are you running on the tags?
I would not think that the super singles flex enough to put extra weight on the tag, could just be a fluke!
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running 110 in the tags which should be plenty but my weight slips are in the coach. I’m pretty sure tag weight is about 15,000#.
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I doubt if this is your problem, but I found out that if I put a front tire on the tag axle that tire had to be perfect with no unusual wear pattern.
I had steer tires that had cupping on the edges. Not excessive, but it was noticeable. So I moved the steer wheels to the tag rather than putting the tires on the drive. Within 2000 miles the tag axle had destroyed the tires by wearing the rubber in the areas of cupping all the way down to the steel belts. This was on a 3 year old coach.
I will no longer place any steer tire on the tag, something that is now an issue with 315s on the drive only and 365s on the steer and tag.
I have no scientific data but for some reason I have seen other issues on tag axle tires such as “rivering” and I do not know why that is the case. I do run my tag axle tires at the lowest pressure listed in the Michelin chart because the load on the tag is lower than the lowest listed axle weight. I use the lowest specified pressure. So far, so good. I almost never lift my tag axle when turning. I have to be in a really tight spot before I would even dream of lifting the tag. If the steer axle tires can take the excessive side forces under such circumstances, my tag tires sure can.
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We rotated 2 365 steers (44wk of 2012) to tag in Apr 2014. Lost one leaving OKC in Oct (4k mi). Pulled sidewall off for about 14 in. from outside first tread row. Had to get a tire at Prevo DFW (ouch) and put the other one on at Jeff’s ten days later. Re-thinking the practice of steers to tag. Geo.
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Interesting..has anyone spoken with Michelin re rotation from steer to tag?
1999 XLV X-6872, liberty #440 -
I haven’t. My issue happened about 23 years ago and I just assumed that the tag had so little weight on it relatively speaking it did not have the ability to remediate a tire as effectively as the drive did.
I don’t know what anyone else’s experience is, except to say none of us likely have enough tag axle weight to justify the size tires that are installed. Now with 365 tires on the tag on a lot of coaches it is nothing more than a place to store a steer axle spare tire.
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I have over the road semi trucks and when I went to the tire company that take care of the tires for my trucks and ask them about rotateing my steers they said they thought I would have better luck if I rotated them to my drive axle. They said if there was any irregular wear which there most often is on a steer tires it would be staightened out by putting them on the drives.They said that free rolling tires often develope irregular wear so by putting them on the tag it would just continue or even get worse.
That was only about five thousand ago so the jury is still out.
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That has been my experience as well, rotate steer to drive and it solves wear problems. I did this on my Duramax Dually that was very heavy and often started getting funny wear on the fronts.
Also, I found that running the drives for awhile and then putting them on steer made the front last much longer and wear better. I later heard that car haulers had much better success putting a drive tire on the steer after about 20k miles or so on the drives, guess as they are really heavy on the steer axle all the time.
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Back in the early ‘70s when Lincoln first went to radial
tires (Michelin) we as service department employees were trained that whenever
moving radial tires the rotation should never be reversed. In other words always keep the tires on the same
side of the vehicle. Changing the rotation direction (we were told) would cause the rubber to separate
from the wire wrapping. I had my doubts,
but as service department manager followed Michelin’s instructions.I wonder if those writing on this topic who had trouble
moving tires from steer to tag changed the rotation and if so, perhaps that
could have something to do with the failure. Likewise, is it possible that the
truck operators when moving tires retain the direction of rotation and
therefore don’t experience the same condition?I’d be interested in knowing if the direction of rotation
was changed or maintained in the mentioned cases.Over the years I’ve moved radial tires around on my own vehicles changing rotation direction without incident, but never on a heavy vehicle like a bus or truck.
Additionally, I’ve never seen a radial tire ‘straighten out’ once a wear pattern is developed, regardless of where it’s placed on the vehicle.
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These are not directional tires far as I know…hell even on motorcycle road race tires that are directional I see people flip rears to get more life out of one side of the tire.
I think once a tire gets a wierd wear pattern from a problem that gets corrected, getting it to stop that wear is a problem when kept in the same position, a steer moved to rear would in most cases stop it I think. No expert, just my personal experience.
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According to the training we were given back then by Michelin reps; we were told that once a radial tire is placed in service it becomes a directional tire.
As I mentioned, I had my doubts about that, but now I’m just interested in knowing if the direction of rotation was changed in any of the mentioned cases. Not implying any cause for the problem – just inquisitive!
Moving a radial tire may stop the wear pattern from getting worse, but will not correct it.
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Ours were rotated front to rear same side. Tires not dis-mounted. Geo.
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Mine was kept on the same side so the damage had nothing to do with direction.
It sounds like once our tires are at a given spot they need to stay there in the case of the 365 / 315 set up. If the tires were all 315 then we can put them on the drives.
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Perhaps I have this figured out!
Tires are rated by the load carrying ability of the sidewalls which is regulated by air pressure.
When a tire is on the steer axle wearing unevenly it nevertheless is carrying
the load on both sidewalls, even though on the steer axle the load is constantly
shifting. Uneven tread wear is ‘usually’ caused by improper toe adjustment. With
improper toe adjustment tire wear is caused by dragging the tire, but the load
remains pretty evenly distributed to both sidewalls. Same goes for cupping and scalloping caused
by out of balance or wheel bearings. Also, keep in mind the tire is new at full
strength when installed on the steering axle and carries more air
pressure.When an unevenly worn used tire is moved to the tag axle two
negatives happen: One, the weight is no longer even on both sidewalls as the
side with the most thread carries more of the weight. Two, the air pressure is
reduced accentuating the condition. Here’s a test to prove my point. Stand in one position with a small shim under
one edge of your shoe and notice your weight shift to the opposite side. I believe that’s what happens when a tire is moved
to a ridged position with uneven tread depth.So you might ask; why then if the same tire were moved to a
drive axle it would perform properly. My
guess: The tire doesn’t carry as much weight (it has a helper next to it) and
the air pressure is set higher on that axle.Okay, you might think this is a lot of bull-pucky, but it
sounded logical in my head. JOne other scenario that causes many drivers of RVs to have
tire troubles is the failure to weigh the coach side-to-side and inflate both
tires based on the heaviest side of the axle. This would be critical when
moving a used tire to a lighter axle – especially on a coach with slide-outs. -
Anecdotal evidence is still evidence. For us, now that we have new tires all around (365 tag and steer), no more moving steer to tag. Just replace all at once. We’ll only have a 6 mo. difference in the 315 drives because we couldn’t get them in April when we wanted to. So, we’re set through 2019.
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