EUC in 12 Days for M35A3 at Sparta

[goodguyzy]

great story, that blow out really is making me think twice about my tires. I do agree that the A3 is bouncy due to the flat spots in tires. makes weird noises that are not normally heard in the A2, i think on account that the A3 is much quieter. the only thing that I disagree with you about is the A2 is easier to start than my A3 in the cold. If its 25 or below, i must use ether to start the A3. My A2 does not have ether and starts OK. Now that you have that A3 are you going to sell the A2? They are nice are they not? easy to get used the comforts of an A3.

BTW, my heater will run me out of the truck, even at 20 deg.

 

[schwenk industries]

That Same thing happened to someone on here ii cant remember but they said that they had brand new looking tires and they to had them explosively blow out, then someone said something about how those tires are prone to explode randomly or something like that i don't quite remember. i would post a link but haven't got clue when i searched.

 

[glcaines]

was the tire that blew one of the tires that was low when you arrived ? I have heard sitting flat or very low for a long period of time ruins the tires and they are destined to blow if used after being flat for a long period of time .

All of the tires were low when I picked up the truck. One was completely flat, but that was not the one that blew. The one that blew was perhaps 1/3 low on air, similar to most of the tires. I agree, a tire being completely flat for a long time is not good.

 

[glcaines]

the only thing that I disagree with you about is the A2 is easier to start than my A3 in the cold. If its 25 or below, i must use ether to start the A3. My A2 does not have ether and starts OK.

I should have qualified that statement. After picking up the A3 and having the original start, the coldest I have started it was 23 degrees and it had been cold for over 24 hours. It started right up without ether after turning over about five times. It ran very rough for a few minutes, but did start. I agree that the A2 with the multifuel engine is normally a very easy engine to start due to the high compression. I seldom need to use ether on the A2 and then only in the low teens and usually only one shot is required.

 

[clinto]

Gary, we're glad you're alright but it sounds like you were well prepared and kept a cool head during the emergency.

I guess clintogf and I are going to have to come visit soon so we can compare the A2 and A3 side by side.

 

[mktopside]

Knowing how the CTIS deflates a tire by triggering the wheel valve to vent externally, I wonder if the CTIS went to let some air out of the tire because of the increase in pressure from driving on the highway..... And the wheel valve stuck open letting the tire run low enough on air to cause the remaining air to superheat from excess sidewall flex. If the wheel valve was stuck in the vent position, the CTIS would have been unable to recheck the tire pressure. If you were going fast enough, this could have happened quickly.

Granted I'm pulling all of this out of my butt, but that tire blew from heat. If it was hit enough to catch fire, and that heat didn't come from a seized bearing or a stuck brake shoe; it had to have come from the tire running low enough on air for that air to get hot.

Just a guess

 

[Speddmon]

That tire is just one example of why I prefer not to have a singled out truck.

 

[glcaines]

Gary, we're glad you're alright but it sounds like you were well prepared and kept a cool head during the emergency.

I guess clintogf and I are going to have to come visit soon so we can compare the A2 and A3 side by side.

You are most welcome to visit any time!

 

[glcaines]

Knowing how the CTIS deflates a tire by triggering the wheel valve to vent externally, I wonder if the CTIS went to let some air out of the tire because of the increase in pressure from driving on the highway..... And the wheel valve stuck open letting the tire run low enough on air to cause the remaining air to superheat from excess sidewall flex. If the wheel valve was stuck in the vent position, the CTIS would have been unable to recheck the tire pressure. If you were going fast enough, this could have happened quickly.

Granted I'm pulling all of this out of my butt, but that tire blew from heat. If it was hit enough to catch fire, and that heat didn't come from a seized bearing or a stuck brake shoe; it had to have come from the tire running low enough on air for that air to get hot.

Just a guess

I agree that there was extreme heat build-up. However, the CTIS was turned off during the trip. Once I inflated the tires to 45 psi with the CTIS at the start and confirmed the pressure with a tire guage, I turned it off. After the end of the first hour, I checked the tire pressure in all tires with the tire gauge. They were all holding pressure. I checked the pressure in all tires manually again, after about 400 miles. Again, all were holding pressure fine. I didn't check any of the tires after that with the gauge, but looked at each tire when taking on fuel. None were looking low on air, although sometimes it can be hard to tell. After the blowout, I checked the other tires and the spare. All were indicating between 44 - 45 psi. Additionally, although the weather was very cold and the truck was standing on snow and ice, all five remaining tires were VERY hot to the touch. This would indicate to me that there is a lot of heat build-up in that type of tire due to flexing. Imagine what the tire temperature would be in hot weather or with a load in the bed. After mounting the spare, the CTIS was out of commission due to the damaged fitting.

This morning, I checked the pressure in all six tires after the truck has been sitting four and a half days since my arrival and all are indicating 44 - 45 psi.

I was also very glad that the tire that blew out wasn't on the front!

 

[flyxpl]

I am not an expert , but 45 is probally on the low side . The tires are rated for up to 80 psi at max load . The problem is the A3 rims are rated for 60 psi max . My A3 does have the 45psi stenceled on the fender though .

 

[mktopside]

I agree that there was extreme heat build-up. However, the CTIS was turned off during the trip. Once I inflated the tires to 45 psi with the CTIS at the start and confirmed the pressure with a tire guage, I turned it off. After the end of the first hour, I checked the tire pressure in all tires with the tire gauge. They were all holding pressure. I checked the pressure in all tires manually again, after about 400 miles. Again, all were holding pressure fine. I didn't check any of the tires after that with the gauge, but looked at each tire when taking on fuel. None were looking low on air, although sometimes it can be hard to tell. After the blowout, I checked the other tires and the spare. All were indicating between 44 - 45 psi. Additionally, although the weather was very cold and the truck was standing on snow and ice, all five remaining tires were VERY hot to the touch. This would indicate to me that there is a lot of heat build-up in that type of tire due to flexing. Imagine what the tire temperature would be in hot weather or with a load in the bed. After mounting the spare, the CTIS was out of commission due to the damaged fitting.

This morning, I checked the pressure in all six tires after the truck has been sitting four and a half days since my arrival and all are indicating 44 - 45 psi.

I was also very glad that the tire that blew out wasn't on the front!

Well, I'm at a total loss then.

Certainly is strange, but you handled it like a pro and you didn't miss a beat!

I have been DDing my A3 for the past few weeks (80 miles a day, half highway, and the rest is mixed heavy traffic and slow city driving) mainly to wring out any issues and just because I love driving it. I work at a car dealership so when I find something I can fix it later that day at work.

I'm going to start checking the tire temps with the IR gun daily to see if I can get us all a baseline on the temps were dealing with. I do agree that running a higher psi would be worth it. I know the CM CTIS modules are programmable, I wonder if CM would be willing to reflash them for us for a fee. Maybe they could set "highway" to 56psi?

I know they have an add on option called "kneeling" and a bunch of other options I'd be interested in. Don't know if they sell to individuals though.

 

[glcaines]

Well, I'm at a total loss then.

Certainly is strange, but you handled it like a pro and you didn't miss a beat!

I have been DDing my A3 for the past few weeks (80 miles a day, half highway, and the rest is mixed heavy traffic and slow city driving) mainly to wring out any issues and just because I love driving it. I work at a car dealership so when I find something I can fix it later that day at work.

I'm going to start checking the tire temps with the IR gun daily to see if I can get us all a baseline on the temps were dealing with. I do agree that running a higher psi would be worth it. I know the CM CTIS modules are programmable, I wonder if CM would be willing to reflash them for us for a fee. Maybe they could set "highway" to 56psi?

I know they have an add on option called "kneeling" and a bunch of other options I'd be interested in. Don't know if they sell to individuals though.

The tires themselves are branded on the sidewall as maximum 60 psi under full load, cold. The tires likely would do much better with a higher pressure on the highway. I think a significant part of the problem may be the age. As I mentioned earlier, the spare had a manufacture date of 05/88. At least that tire is 22 years old. There is zero sign of dry rot on any of the tires, but there could be internal dry rot. I also don't know what was done to the tires before I picked up the truck. Could be someone ran the truck with the tires half flat and damaged them.

 

[goodguyzy]

I am not an expert , but 45 is probally on the low side . The tires are rated for up to 80 psi at max load . The problem is the A3 rims are rated for 60 psi max . My A3 does have the 45psi stenceled on the fender though .

my A3 has 50psi stencilled, i have the CTIS off, and manually fill to 50. In the near future i am going to disconnect the CTIS.

 

[glcaines]

My A3 does not have the tire pressure stencilled. The CTIS maxes out at 45 psi for highway operation. The TM specifies 43-47 psi for highway use.

 

[goodguyzy]

? sounds like the military is SNAFU

 

[OSO]

I used to work at a crane yard .I had to move our 75 Ton hydraulic crane weight appx 126,000# on 4 axles . Tires 14.00x20 I went past my permit route , and stayed on a freeway .Tire blew out on right rear outer dual .I could feel the crane drop at the rear ,limmped off the freeway let the other tires cool off then crawled back to our yard . Those big tires still build up heat.

 

[glcaines]

I used to work at a crane yard .I had to move our 75 Ton hydraulic crane weight appx 126,000# on 4 axles . Tires 14.00x20 I went past my permit route , and stayed on a freeway .Tire blew out on right rear outer dual .I could feel the crane drop at the rear ,limmped off the freeway let the other tires cool off then crawled back to our yard . Those big tires still build up heat.

The other extenuating factor is that the tire blew after ~700 miles of continuous driving. The only cooling off period was during refueling. I'm sure this contributed. It would have been much worse in hot weather.

 

[flyxpl]

Tires on my A3 state max load 7165 at 80 psi cold . The A3 rims are stamped max pressure 60 psi . I did drive my A3 350 miles from Sparta this august in the heat with no problems .I believe I left with over 50 psi in my tires .
A friend of mine in the gaurd told me that the hemmitts have big problems with tire heat when they get on the interstate .

 

[glcaines]

Tires on my A3 state max load 7165 at 80 psi cold . The A3 rims are stamped max pressure 60 psi

Are your tires Michelin X? Mine are Michelin X and they state 60 psi cold. My rims are stamped just like yours.

 

[goodguyzy]

just out filling up my A3 tires and noticed it says "for dot test and highway use in north America and Australia" on the Mich. X 14.5/20. I guess they are to big and manly to be used in Europe.