Tire problems and tire pressure monitor

[tbutler]

We had a flat tire on the outside rear when at the FMCA Convention in St. Paul last year. I had the flat repaired on site and then replaced the worn tire at the local Wingfoot (Goodyear) dealer. The best I could do was to get tires about a year and a half old. So I took them (a matched pair).

Two years earlier we had a blow out on the drivers front tire at highway speeds. The tire that blew had been in service for three years. Besides destroying the wheel the blown tire took the exhaust pipe off the generator and did some minor damage to the coach exterior right by the wheel. I was able to keep the coach on the highway and get it to the shoulder. Thank goodness no other vehicle was in our vicinity. The blown tire did pull me completely into the passing lane before I could get control to bring the coach back to the right shoulder. If my wife had been driving I'm not sure that she would have been able to control the coach. A driving safety course at the FMCA Convention in Redmond in 2004 was instrumental in preparing me to cope with this emergency. I heartily recommend that course when you next attend FMCA.

We had been having a great deal of trouble with that pair of tires as they caused excessive vibration. A Wingfoot tire shop in California identified the problem as being out of round. As a result, I replaced both front tires and made sure that they were mounted as steer tires. The difference as explained to me is that the steer tires should be inflated to seat the bead with the tire in the horizontal position. This ensures that the wheel is centered in the tire properly. If the tires are in the vertical position the wheel will seat lower in the center of the tire as it stands. When you drive it, it will vibrate up and down as it rotates. In addition, tires are slightly out of round when manufactured. So are the wheels! Now when I have new tires mounted, they are tested for round after mounting. If they are not within .006 inches of round, they are removed and rotated on the rim to ensure that they come within this standard. I had to personally supervise this at the shop in St. Paul. They initially mounted the tires vertically and when I called them on it they corrected it. After that I watched them like a hawk, checking the instrument as the tires were tested for round. At one point I had to face down the shop supervisor who wanted me to leave the shop. I told him that I would be glad to be accompanied while in the shop if he wanted to do that but that the actions that I had seen up to that point indicated that I needed to be personally supervising this job. He walked away and left me to continue working with the installer.

I have started replacing the front tires on the motor home every 2 years. The old front tires go on the rear axle and the oldest pair on the rear come off and are scrapped. Using this system, the oldest tires on the coach will be six years old when they are removed not counting their initial age when purchased. Everything I have seen and read indicates 7 years for tire age before retirement. The oldest tires are on the duals in the rear where a flat is less an emergency. Besides the advantage of keeping fresh tires on the front of the motor home, this offers the advantage of not having to put out $3000+ for a complete set of new tires in one purchase.

I check tire pressure every morning before the sun hits the tires when we are driving and monitor tire temperature by feel at every stop. I purchased and installed a full Pressure Pro system for the motor home and the toad at the St. Paul Convention. It is very reassuring to have a monitoring system to alert me to any changes in pressure while driving.

The only alarm so far occurred on a very hot day (100+) when we ended up in stop and go traffic after extended highway travel from a cool mountain start. The tires on the sunny side of the coach (outside rear and steer tire) exceeded the Pressure Pro factory set limits for high pressure and the alarm sounded. There was no missing the alarm, it was plenty loud. I could dismiss it but it would return after a short interval. It was somewhat distracting when driving in heavy traffic. Since tire pressure had been set correctly at the beginning of the drive I knew this was not an emergency and was not worried about tire failure. It did take some explaining to my wife as to why this was OK. As soon as we cleared the traffic and were moving again, the tires cooled and the alarm didn't sound again.

We occasionally will have one sensor on the toad drop out. I have the monitor mounted on the outside wall on the drivers side of the coach. The tire that drops out is the rear tire on the opposite side of the toad. I'm sure that an antenna extension would solve this problem. Since it is intermittent I haven't resorted to the antenna boost.

I do find a few pounds difference between the Pressure Pro monitors and my tire gauges. Like my wife says, "A man with a watch always knows what time it is. A man with two watches never knows what time it is." I always set tire pressure by the lowest reading gauge and allow 10% above the recommended tire pressure for the weight being carried.

I thought about purchasing a set of tire monitors for a number of years. It took the above events to finally convince me that I couldn't afford not to have them. Considering cost, peace of mind and safety, tire pressure monitors are an excellent investment. The Pressure Pro system is easy to use and is completely portable if/when we ever change coaches. In addition, I can move the monitor from the coach to the toad to monitor tire pressure there when we are out for a day trip. When I check tire pressure manually it doesn't reset the pressure setting unless it is off the stem more than a minute so it is no different than taking a regular cap off the stem. If I adjust tire pressure the new pressure setting is accepted after one minute off the valve stem. It usually takes me that long or longer to adjust the pressure so this is convenient also. I have not replaced the short rubber stems on the toad and they work quite satisfactorily. If the toad had long rubber stems I would replace them.

[TZScales]

Thanks for sharing this important information. We recently purchased the Pressure Pro system for six wheels and I will install it this weekend. We plan on adding a toad by mid-summer and I will purchase four additional tire monitors, and will also have my toad's valve stems changed over from rubber to metal.

[ttt1953@gmail.com]

Excellent information. I enjoy reading your post under the various topics. I noticed you did not mention balancing. I've read various opinions and would like to read yours.

Thanks, Tom

[tbutler]

Hello and welcome ttt1953,

As to the balancing of the tires, I am old school. I have the steer tires balanced when installed and would re-balance if necessary or if they were off the motor home at any time. Their out of balance condition is easy to sense in the steering wheel. My preference is always to have the tires spin balanced. I have been satisfied with static weights installed on the inside of the rim. There are more elaborate systems but I can't see the need for them with the limited mileage we put on motor homes. I'm driving 15,000 miles a year, not 150,000+ a year like a professional trucker. My tires will still have usable tread on them when their lifetime is over.

I have talked to several tire people and they don't recommend balancing the rear wheels as they will be in pairs and one minor imbalance should cancel the other in most cases. I've never noticed a problem with balance on the rear axle either in ride/handling or in tire wear.

If you are asking about the affect of the pressure pro units on the valve stems, their weight is insignificant in relation to the full weight of the wheel. Even in a dynamic situation their effect is negligible. I'm not sure of the weight of a single sending unit, I could look it up but it must be less than an ounce.

By the way, the Pressure Pro recently alerted me to a low tire on the toad. We were in an RV park and I was going to bed for the night when I heard an alarm. It was the right rear tire on the toad. I noted the pressure, shut the unit off and went to bed expecting to have to change a flat tire in the morning. When I got up, the tire pressure was about 2 pounds lighter than the night before. I wouldn't have noticed if I hadn't been alerted by the Pressure Pro. I drove straight to a tire shop and had the tire repaired. It had a large bolt in the tire. They repaired it and I was on my way once again.

For TZScales, welcome also. I am having a new set of tires installed on the toad and will have metal stems installed in my rims.

[garykd]

Hi ttt1953,

I balance all 6 tires. For me, not balancing the rear tires may produce extra wear and tear on the rear suspension components. Balancing is cheap insurance. The idea of one tire canceling out another tire's problem is depending on luck. Since nobody is in the rear of the coach, when moving down the road, I do not think an out of balance condition would be noticed by those sitting in front of the front wheels.

I've had the PP system for 4 years. On the coach, my wheels have valve extensions on them. The PP sensors do put some radial pressure on the stems. Several of my PP sensors have gouges worn in them from rubbing against the wheels. On the toad (05 GMC ENVOY XUV) I started by just installing the sensors on the rubber valve stems. The stems didn't last a year. I switched to rubber stems with a metal insert. Same result. So, I bit the bullet and put in all metal stems. This has worked well. There have been no additional problems. If you have PP sensors on rubber stems, monitor them closely.

The reason I took the toad in steps was the cost of the all metal stems. Because of the curvature of my GMC wheels there was no after market stems available. I had to purchase everything from a GMC dealer. The all metal stems are for later model vehicles and have the tire PSI sensing unit built into the stem. I can not use this feature, but that is the way the stems are made. They are very expensive.

[tireman9]

TBUTLER

Great write up.

The high pressure warning was probably due to brake heat soak after the long downhill drive.

Your item about the warning of the low tire on your toad shows the value of a TPMS.

One only has to consider the potential cost of

1. a tire failure plus

2 potential damage to the toad to offset the cost of your TPMS.

[tbutler]

Thanks Tireman9!

I'm enjoying learning about tires from you!

The high pressure warning was a temperature thing. We had been near Crater Lake in Oregon and were in Sacramento when the alarm went off. We had been at altitude in Oregon for some time and I do adjust pressure to keep it on target for this kind of change. Coming from the mountains and the cool temperatures into a near 100 degree day in Sacramento and then sitting in traffic with the sun shining on one side of the coach was I think the cause. At least the sun was the final factor as the tires on the shaded side of the coach were not affected. Their pressure was high but not high enough to set the alarm off. Even the inside dual on the sunny side was not affected, only the outside dual and the front tire on the coach.

For Gary, I have been in the rear of the coach when Louise is driving and have never noticed any unusual vibration from unbalanced tires. It is also possible to sense the vibration of the rear tires in the drivers seat. The vibration of the drivers seat is primarily a result of the rear of the coach while the steering wheel action is a good indicator of the vibration of the steer tires. I'll balance the rear tires next time and see if I can tell the difference.