Ouch

[Gordy]

With any luck, DOT won't take him to the scale.

[bushpilot]

whats the story gordy ?

[Gordy]

Supposedly a racer coming out of RMR raceways (Utah) this weekend. Reported that a tire blew out but I don't see any rim or spindle left.
Be interested in seeing what was on it for suspension and tires.
After my conversion I upgraded my 315's to 365. This allowed me to run less pressure but at the same capacity.
Wasn't cheap because I installed the wider ALCOA rim for the increased size but it sure rolls nice.
I really pays to scale all rv's so we know what is safe and what isn't.

[bushpilot]

i just read this one the other day.....I'm still wondering what would cause this....and how no one was killed !




source --> http://2010liberty.wordpress.com/201...ge-of-scenery/

[bushpilot]

just got some info from the coach owner regarding the above wheel.
I asked what he thought caused the wheel to be torn from the axle/hub & studs.

I also was asking for confirmation that the wheel was steel (looked like it but wanted to be certain).

We think probably the wheel was over tightened sometime in its life causing it to start cracking between the lug holes. Continued use just aggravated the situation until it broke. And yes, it was a steel wheel.

[Gordy]

That broken center is really not all that uncommon. Want to know the cause-look at the inner tire/wheel-FLAT. Rim is overloaded from the weight that should have been distributed over the dual.

[bushpilot]

Originally Posted by Gordy

That broken center is really not all that uncommon. Want to know the cause-look at the inner tire/wheel-FLAT. Rim is overloaded from the weight that should have been distributed over the dual.

how can you tell that the inner tire is over loaded ? the inner tire is FLAT.

The accompanying story says the outer tire busted the inner tires valve stem when it came off.

[Gordy]

"Typically" this failure was caused by running the other tire flat. Okay he says that the inner went down when the outer separated but most cracked rims I saw where from flats, loose nuts or overloaded. (I put 40 years in wrenching on and off road equipment)
I realize that these are not aluminum rims but Alcoa has an excellent website with rim maintenance discussed in http://www.alcoa.com/alcoawheels/cat...al-English.pdf

[bushpilot]

I trust what you're sayin' Gordy, i figured you hadn't seen the sorry. I've never seen a wheel like that - wonder someone wasn't killed. cant wait to look at the alcoa site, thanks.

[Gordy]

Don-not a problem. Take another look at the pic and notice that the bus had the older style budd wheel nuts, that use an inner and outer nut. This will keep the inner in place should the outer have this kind of failure.
Most newer vehicles are "unimount" style-that means the hub carries the weight and a single nut and integral washer (per stud) hold both rims in place. Real ugly when they part company.
Now if you overtorque these nuts and over stretch the bolts, they will break under the right circumstances-again an ugly situation.
These pics are examples why we should weigh our rigs, do a proper pretrip inspection and know a lot more than where to put fuel and how to start the coach.

[hot rod]

Here is the relevant statement: "when the source of the noises he'd been hearing became evident". So the wheel was cracked and getting worse to the point of making noise (which is really bad by that point) and he just kept driving until it completely failed and fell off the truck. It's got to be making a hell of a racket to hear a right side outer wheel from the driver's seat. Regardless of what caused the CRACK, which could be simple metal fatigue on an older coach like that, or negligence such as over torquing as some have suggested, the cause of the FAILURE is the driver didn't bother to pull over and figure out what was making noise until the tire passed him. And just because the inner valve stem got ripped off in the accident does not mean the inner tire had any air left in it at the time. Realistically, what do you think the odds are of that inner tire having been checked with an air gauge any time in the recent past? As much as the D.O.T. is a pain in my ass, it scares me more that the average untrained grandpa (nothing against us old guys in general) can hop into a piece of equipment just as heavy and complicated as anything I drive with my cdl and tear off down the road with no license, training, pretrip inspection or any sort of accountability. Ok, enough soapbox for one day.

[Bob86ZZ4]

I agree with hotrod about that valve stem. First thing I thought was the inner tire was flat long before the outer rim cracked off. Maybe the valve stem was gone before the incident too? I sure do like having my Pressure Pro tire monitoring system!

[bushpilot]

as bob says....w/out a tire pressure monitoring system how would any driver ever know.
imo these TPMS/Temp monitoring systems should be mandatory for any coach owner.

for me the surprisingly unexpected benefit is that I mess w/ the tires A LESS (at least from a tire pressure checking perspective)....no more dragging out hoses (anticipating that ill need to add pressure) or avoiding pressure checks because i don't want to pull the equipment out....now i just turn the monitor on and KNOW what the state of each tires pressure is.

I still, visually, inspect every tire when i fuel up or when we stop (when I'm putting boards under the jacks) and before we depart...but no more tire pressure checking w/ a gauge.

[hot rod]

I love my tpms system, like Don says, way easier day to day. None of us really wants to get down there and check a whole bunch of tires every time you leave the driveway so inevitably it gets skipped from time to time even for those who maintain religiously. Plus peace of mind rolling down the road. And the money even adds up properly, figure out what a new tire and a road call would cost you for a blowout to get fixed (even if it doesn't tear up the coach) when you can generally save the tire if you catch a slow leak before it goes flat, overheats, and ruins the tire. Saving even one tire can pay for the system.

[bushpilot]

as hotrod says !

After a trip i had put the coach away and left it for a couple of weeks....then prepared for the next trip (generally when i put the coach away i level it and raise it off the concrete & put a bit of air between the tires & the floor, to keep from flat spotting the tires).

I turned the TPMS monitor on while i did some other tasks and discovered the front left tire was low...discovering i was down to 70psi....i aired the tire up & got the soap/bubbles out, but couldn't find the leak....home i went (knowing id come back the next day)....and again the tire was down around 80 psi....eventually i discovered the leak was at the wheel where the valve stamp mounted.

I aired the tire again and the next day topped it up - able to drive it to the tire shop (very VERY slow leak) where they replaced the valve stem (for free) !

w/out a TPMS system i might not have caught the problem - i may very likely have ruined a fairly new tire...but w/ the TPMS system i was alerted (even when parked in storage) to the issue & avoid a service call !