Beautiful Sky Country

[ARD]

Glad you are okay @redbaron! Keep safe out there.

 

[Neal]

@redbaron obviously you had a sidewall failure. My tag tires had cupping and an odd wear pattern before replaced and it makes me think of the stress and forces put on these tires when in reverse AND turning. I think any type of turn in reverse is dragging these tires putting forces on them (lateral) that they are not designed for.

As we know "tag dump" is not "tag raise" it's just letting the air out of those bags, how completely who knows and how long do we wait as drivers before putting it in reverse and going in motion? Airbags take time to deflate, I bet most of us never wait long enough for that to occur.

With HWH Active Air, I had to ask for tag dump to be programmed in, it is not the default. With your system, do you know if in fact your tag is dumping? Regardless, with the weight on your coach and higher, I really saw it with King Aires when at Newmar, they have tremendous aft weight it appears. The side force has to be pretty bad on those tag axle tires. Something to be aware of, both tag dumping or not, and making any turns when in reverse.

 

[Jim]

For those of use who don't know, can you explain "tag dump" please?

 

[Texas Clodhopper]

For those of use who don't know, can you explain "tag dump" please?

For those of us with a Freightliner Chassis, when we put the Allison in reverse, we should wait a few seconds until we start backing up. This allows the tag airbag to deflate, and the tag tire will steer more easily.

 

[redbaron]

The tires were inspected 2 days prior and 1100 miles prior. All 8 tires inspected by southern tire mart. They suspected another tire, but did not see any visible wear, damage, or checking.

What they did not do is remove and balance as I was not willing to spend money on a rear tire that showed no issues.

That was another mistake. The wear you see and further sidewalk happened after the explosion that was in the tread about 3 inches from sidewalk. When the tire exploded, it stopped spinning and I drug it across lanes before it started to spin and walk off. I then slow drove it until it was evident I was about to be on a rim, and stopped.

None of the things we where told to watch out for where evident except for the shimmy. That is something I knew was a problem but didn’t realize all tires play a role in. Next time I will spend the extra 2 hours to get all balanced and road force tested.

 

[Texas Clodhopper]

@redbaron , I also use Southern Tire Mart, one in Shertz or the one in Buda, TX. I'm not aware that either store does the road force test.

 

[Neal]

For those of use who don't know, can you explain "tag dump" please?

When putting the coach in reverse, the tag axle airbags release their air to take weight off the tires. They don't technically lift. In my 2017 Ventana pre-ActiveAir there was a switch that controlled it, now with HWH ActiveAir it's controlled by the system. I don't know how it works in other Newmar's but if you have an option to turn it on/off/auto, review the setting.

 

[osuallen]

@redbaron obviously you had a sidewall failure. My tag tires had cupping and an odd wear pattern before replaced ...........................

In camp Freightliner, they recommended running 90 psi in rear even if tire charts showed lower was allowed. They said they noticed weird and irregular wear much more frequently under 90 psi. May or may not be true on Spartan.

 

[redbaron]

90 psi has always been my low point on drive and tag. Charts call for 85. Summer I run 95 because that’s where the winter 90 ends up.

 

[Roadglide117]

i wandered what type sensors you had. I have TST and when I blew a tire alarm went off immediately.

 

[DennisT]

i wandered what type sensors you had. I have TST and when I blew a tire alarm went off immediately.

Been running the TSTs for 10 years - saved us twice and were immediate alarms.

 

[MarkMaxPayne]

Did the TPMS show anything off on the tire temp before it blew out? Although I have warnings set for both PSI and Temps, I often leave my TPMS on the temps screen. Glad things worked out with no major damage or injuries. Best...

 

[d23haynes57]

At the time of the incident, I was doing 54mph. This was a 5% uphill grade, with outside temps of 80F and a total distance traveled from cold of 15 miles.

I heard the explosion and thought it was my front tire and was thinking how amazing the retrobands are. I was passing a semi on the uphill climb and had to let off gas to move over. As I moved lanes I could visually see the tag tire wobble and I allowed my speed to continue to drop naturally as I eased to the shoulder. I then drove about 100 ft, trying to get to the most visible spot when I noticed the tire working off the rim. I stopped there.

I mentioned earlier about a wobble. This started last year leaving Texas for glacier. At that time it was only at 68-70 and not below or above. On the return trip last year it became more pronounced below 60, but 62-68 was fine and that’s where I kept it.

I always assumed it was steer tires as it was felt in the steering, mirrors etc.

This winter I rotated the steering tires and checked them visually while off the coach. They looked great.

we left for Montana this year and noticed a terrible shimmy starting at 25 and staying strong until 62. It was so bad we couldn’t see out the mirrors or keep anything on the table without it bouncing off.

I took the coach to southern tire mart and had them test steering wheel balance. It was off and the rebalanced and did a road force test for runout. Told me tires are now perfect. The shimmy never left and I figured I had a hub, bad tire, or combination. 64 was tolerable.

After this blowout, the coach drives like a Mercedes. No wobble at all at any speed.

Lesson learned: you can’t tell which tire is bad by the feel. Any shimmy or speed related vibrations are potentially a tire giving up.

I will be putting 6 toyos on the rear before I return home.

I am late to the party here. Traveling and doing holiday events. Looking at the pics and tire tread, that tire was well worn and internal damage was probably visible if someone caring and knowledgeable took the time to really look at it. Tags get beaten up very bad even with steerable axles, Normal highway travel and turns place side loads and side scrubbing wear on them. That vibration and shimmy was a tire talking to you and shame on the tire shop for not knowing to look at the rears and even try to make a sale. Sometimes tire have to be removed from the vehicle to really be "seen". Even rear drives can set up vibrations that go through the chassis and steering wheel. When they occur, the cause needs to be found and rarely on a motorhome will a re-balance actually fix it. Adjusting speed only delays the inevitable. This past February I had Josman in Orlando replace my shocks and air bags. While the tires were off, I can see that the time is coming. I do not know all the miles, but they are dates around 1421, and I found paperwork that they were actually installed 9/2022. I have no issues with vibration but watching closely and will probably replace the set this fall. Existing tires are Michelin X-Coach, I am considering Toyo. But as I use the coach for winter travel I would like to maintain the winter rating. Only other 3 peak mountain snowflake rated tire for all position use, in my size that I have found is the Yokohama 124R. My last motorhome I actually used drive tires in the rear. I am considering that also but many choices in my size. The Michelins I think Are a bit outrageously priced.
For those asking about the TPMS response they are not real time, continuously updating devices. Some sensors and systems will have an "immediate" alert feature for a pressure change alert. Stil there can be time delay. As for temperature monitoring, if an external, valve mounted sensor that function is somewhat useless. You really get the ambient temp unless you are building up so much heat the area inside the wheels is getting hot. Pressure raise is actually a much better indicator if you know what rise is normal. As a though when that tire failed, that extra weight then became on overload for the drive tires.
I'm trying to be informational here. I think it sometimes stinks that going to the experts we do not get the advantage or real knowledge and experience including the Opps factor. I think there is a tendency to avoid tire service and replacement based on some calendar expectations or looking for a warning sign of failure. Sort of like how any do not replace batteries until there is no choice. Some things are consumables and maybe need to be thought of as old food in the fridge or freezer. My opinion, worth what I am being paid for it, as much as I sometimes call that type of failure "Michelin-itis", the ride disturbance and visual warnings were there. The roadside event could have been avoided.
And of course, very glad no further damage or injuries. If my comments can help just one person avoid a similar event, I would be very pleased.