Nothing impressive—a small landscape study. Tiny, really. But it's more than I've done in a while. I don't get much practice in. I usually don't have time.
This weekend I had plenty.
(warning: boring explanations ahead)
The load on the back wheels of a semi-tractor can vary from less than 10,000 lbs to some 34,000.* That's a lot of variation. So, many modern trucks have an air spring system that automatically adjusts itself to keep the suspension more or less balanced. Part of that system involves keeping the load divided evenly between the two drive axles. That part of the job is handled by a gadget about the size of my palm, called a leveling valve. When it stops working properly, Bad Things Happen.
As I drove down the road the other day, I started noticing a familiar obnoxious noise. A roaring sound that seemed to come from the transmission, every time I let off the gas (or the governor did the same). It was familiar because I've had a truck do this to me before. The leveling valve was over-inflating the air springs.
This had several effects on the truck. The two most obvious ones were:
- The tractor-trailer had the kind of ride you'd expect from something with absolutely no give in the suspension. Ever hear of a small wagon called a buckboard? How about a primitive bicycle called a boneshaker? But perhaps I exaggerate.
- The over-inflation of the bags messed up the weight distribution between the drive axles. It fact, it tried to lift one set off the ground. I don't thing it succeeded, but it did throw them out of line vertically. And that threw the drive shaft out of alignment. Thus all the noise. The fact that it also put strain on the entire drive train is just a bonus...
Obviously I needed to get the valve replaced. Unfortunately, by the time I could get in touch with the Breakdown Dept., the weekend had come upon us. And the company shops didn't have that part. They'd have to get it from the manufacturer. And this manufacturer's service centers don't open on the weekend.
The first fellow I talked to in Breakdown (on Friday night) told me to try a few tricks to get the valve working. I spent the next day trying them. The helped a bit. For a while. Then, about halfway through Saturday I was back where I started.
The fellow I spoke to Saturday told me to call back when I knew where I'd be on Monday. Then they would figure out where I could take the truck to get it fixed. Made sense. So I started east, shutting down that night in Atoka, Oklahoma.
Sometime that night I got an idea where I would be going next. So I called Breakdown and told the third guy I'd talked to about the problem and where I'd be Monday. He said, “Who told you to keep driving the truck in that condition? You STAY RIGHT THERE!”
Then he called the manufacturer's service department. Who called a local shop. Who sent a man in a service truck.
Who arrived late that night. And confirmed that I needed a new leveling valve. And that he didn't have one.
Sigh.
So someone came out yesterday and took my trailer on to its destination. And I sat here all day.
This morning I learned that the nearest service center that had a leveling valve in stock was in Oklahoma City. So the service truck went to get it. A hundred and twenty miles. Each way.
Sigh again.
So I sat most of the day today. I wandered around the Wal-Mart. I drew a picture. I reread both the books I brought with me this trip. I did other things I no longer remember.
And about dinnertime the man in the service truck returned. Half an hour later the truck was fixed. Soon after that I got a new load assignment and started north. I could have driven all night, but I don't like to do that. And I might have had trouble timing my pickup. So I found a truck stop at the Arkansas border and took my break.
A hundred miles or so, in two days. Because of a valve the size of my palm. I'm sure there's a lesson in there somewhere. I'll try to figure it out in the morning.
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*This assumes, of course, a legally loaded truck. Careless loading or a special permit can result in more weight back there.
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