Honk if anything falls off !

          Bias ply tires .... antique trucks with 1930's suspension technology ... you have to expect *some* bumps in the ride, don't you? While some may think getting a comfy ride out of an old truck is the automotive version of making a silk purse from a sow's ear, others relentlessly pursue ...

Grind down brand new truck tires????

My truck is a 1952 B-3 Dodge Power Wagon. It has the original 230 inch flathead 6 motor, and non-synchro transmission. I call it "Kirkwood", after the town in New York state where it served as the VFD brush truck for many years.

On my 1952 B-3 Dodge Power Wagon, that I call “Kirkwood,” I have 9.00 X 16 bias ply Power King tires mounted on the original Budd wheels. Power Kings are an aggressive tread tire, and many in the hobby have them, as well as other very similar brands.

Since finishing the body-off restoration on Kirkwood last in the Fall of 2010, I have been driving it on short trips as well as a few trails, like at the West Virginia Power Wagon Rally in October 2010.

I really like these tires off road and in the snow. They also handle well on pavement when cornering. I cannot say how they are on rain soaked roads at this point, as I have not driven in rain.

However, I had noted a problem with vibration and a perceived slight hopping sensation when I got over 25 mph, that seemed to come and go to an extent at different speeds. This occurred even after the tires were hot and the flat spot is gone.

To analyze the problem and try to balance them, I went to a truck tire business about 30 miles away. The employee there pulled one of the wheels and put it on their balancing machine and told me he could not balance it. It called for 13 oz in one spot and that was too much weight, even if this was a big rig’s wheel and tire.

The man did not know, but said the tire might be "out of round." He was not an especially helpful person, saying basically I needed to “live with it”.  He replaced the wheel lugs using a 1-inch drive pneumatic wrench at a very high torque setting. Back home, I needed a four foot cheater bar on my lug wrench to break them loose. That is a lesson I will never forget!  I must report though, that the manager would not accept any payment for this attempt to balance, which was appreciated.

Before I accepted this balancing opinion completely, I thought I would do a little research. I found that many bias tires, especially the bigger ones like the Power Kings and others with a similar aggressive tread design, could be "out of round." (There it is again.) This condition, I learned, even occurs on some brand new name brand radial passenger car tires, but is most noted on the bigger truck and off road tires.

The fix for being out of round is, in many cases, a tire lathe or truer machine. These machines were quite common back in the day, but are still being sold. There is an interesting You-tube video on their website of the non-portable machine in action.

When I contacted the Tire Service Equipment Mfg. Company, they gave me a list of the shops that had these machines in the Mid-Atlantic area here close to my home.

Additional research revealed that contrary to what one might think, cutting the high spots off a tire that is not severely out of round with the truer actually makes the tire last significantly longer. The out of round condition is very hard on the tire and they have a shorter life. One truck driver I talked to recently said he gets a third again more miles with trued tires vs. non-trued.  Of course, it also gives you a very smooth ride.

There is a post from October, 2010 on a power wagon on-line forum where the author commented about a friend of his who regularly hauls a loaded trailer with a one ton dually truck as a part of his job. This man has his tires trued on every truck he buys due to the positive effects he has seen over the years with tire and suspension component longevity.

I e-mailed a truck repair facility about an hour and a half away that had the machine. The service manager there, Garrit, was quite helpful. He said they could not promise anything until they could examine the tires, and also that aggressive tread tires are tougher to do, but they would be glad to have a look at them.

The business I went to is Elliott-Wilson Trucks, located in Easton, Maryland. It is a big truck service facility over several acres, with many employees and services. Of the whole service staff, only two of the mechanics knew how to operate the truer, and only one handles the tire-truing jobs. Willie has worked as a heavy truck mechanic there for over 30 years and was the man assigned to my job.

After trailering my truck “Kirkwood” to Easton, I drove it around the town for a while to remove any flat spotting. Then I pulled it in to the service bay and Willie got the front end on jack stands right away to get weight off the tires. He examined the tires and said that with an aggressive lug tire like the Power Kings, he could not really true the whole tire tread width like he would do with a more traditional tread road tire. He said the truing machine does not work very well with the outer lugs that are somewhat perpendicular to the middle of the tire. He explained that this did not necessarily mean the tire could not be improved by truing, as most of the contact area on a hard road would be on the center section of the tire, especially when up to speed. Looking at the tire from in front of it with its slightly rounded profile supported that idea.

He first took a tire run-out gauge and showed me that the tires were all up to 1/4" out of round! He then used a metal contour gauge to measure the tire tread profile to set up the truing machine for that specific tire.

He said that if a tire is 1/8" or less "out," they could true it and make it completely round.  With a situation approaching 1/4” and especially in this case, they prefer to not try and remove all the run out, as it would cause a different problem (explained below). But, removing a bit over 1/8" of the run-out would still make things a lot better, as well as enable him to balance them most likely. He added that if he got a tire that was over 3/8”  out of round, then that is too much to true and the tire should be scrapped.

Willie was very patient and meticulous, which is what it takes with this type of task. It took him close to 30 minutes with the initial tire and then about 15 minutes with the others just to set up the machine precisely. Rushing the set up can ruin tires I was told.

The tires are left mounted on the truck with this model of the truer and the machine spins them on the hub. He then started the lathe mechanism and as the tire rotated the lathe knife would start shaving the high spots, and then not “cut” on the low spots. The mechanic must be patient with this process as you can cause damage if you try and take too deep a cut.

Eventually we got the center sections fairly round now. Again he cautioned that if we tried to cut the central area of the tires a full 1/4", it would cause a problem, as the outer lugs would then start to impact the hard road surface while driving more than they were designed to, and he could not cut and round out the outer lugs except right next to the central area.

After the truing was completed, he balanced each wheel / tire on the hub. This involved a strobe and a machine that spun the tires very fast. This machine is also used on the big truck wheels and tires. One thing I like about this is that because you have it on the hub, you are basically balancing the whole rotating assembly, not just the tire and wheel.

After completing three tires, he started on number four. Grossly, the tire and wheel looked like the other ones. When he started to true it, he remarked that it was more out of round than the other three. Then, when he started spinning it to balance it, he could see with the strobe light that there was some lateral run-out at the split ring.

He measured this to confirm his impression and said that this wheel was bent; it could not be balanced. Incidentally, this was not the wheel / tire that the previous tire man said could not be balanced due to the weight necessary.

Luckily I had my spare so we swapped the spare down and he trued and balanced that one.

Taking it for a test drive, the truck had noticeably less vibration and shaking at different speeds. I did not get the slight hopping sensation any more. Of course, if one allows a truck with bias tires to sit for a length of time they will flat spot. But, I made my observations after a warm up period. While noticeably improved, I am not going to say it felt like a modern truck; after all it is a 59-year-old Power Wagon with the stock suspension!

But I can truly say it runs better after truing and balancing the tires. I especially liked that this process was done with the wheels mounted on the hub.

I must add this about the process. After he finished the front two, we swapped front to back. Then he had me drive around again to remove any flat spotting on the (now) front tires from having been on the ground. I drove in the bay and he immediately got the front on jack stands.

If you have a vibration or other problem suggestive of a balance issue, I urge you to look into a having a truck tire shop check them for being out of round, as well as looking at a strobe balancer that can balance the whole rotating assembly.

The maker of the truer machine can supply you with names of some facilities that have the machine. The machine comes in two styles, the off the hub type and the on the hub type. For my purposes, I wanted to have the portable on the hub truer with my truck.

Dave

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