It's so common, it even has a name: the "Death Wobble." It's that vibration that sets in at a certain speed in old cars. I was even told that, "All MG TDs do that at 50 mph." But I knew that wasn't so, because I know two TD owners, Charlie and Jake, who can drive 75 or even more without a wobble or vibration. Significantly, both of them are running wire wheels that were purchased brand new during their cars' renovations. Could I do something for Beck and still use the 72-year-old steel wheels?
Talking with Charlie Baldwin, I knew that he had his tires trued when he first installed them. In independent research, I discovered the very same shop he used - K&T Vintage Sports Cars in Bethlehem, PA. They have one of the few remaining truing machines in service.
When I brought all 5 of my wheels and tires, I was told, "Make yourself at home, wander around and see everything." What I found was a huge shop crammed with vintage cars and racks of parts!
I was particularly taken with this lovely TR3, since I had one when I was 16. I later had a 240Z like the one in the second photo below.
This young tech was in charge of my work. I asked him how long he had worked there, and he said, "Four years - I started right after college." I asked him what he studied in college, and he replied, "Auto restoration, plus an extra year of CNC Machining." Well, that inspires confidence! In this photo, he's measuring the radius of the curve of the tire tread to correctly set up the machine.
In use, the tire spins slowly, and the rotating cutter at 3 o'clock trims off the high spots. He told me that even brand new, expensive tires are rarely perfectly round. The control at his left hand moves the cutter back and forth, following the radius he previously measured and set. His right hand slowly advances the cutter forward. He was extremely careful to remove the minimum rubber possible. It took about an hour to true all 5 tires.
Here's a brief video showing the process. You can see rubber particles fly when the cutter encounters a high spot.
Once all five tires were trued up, he moved to a modern spin balancer to balance the tires. I watched as he carefully zeroed out the imbalance on both sides of the wheel.
Well, it was definitely better, but I didn't get the perfect results that Jake and Charlie got with brand new wheels. I experimented with moving different tires to the front axle, and my fourth attempt was the best. Before, Beck would consistently start vibrating at 52 mph. Now, 60 mph is smooth, and I drove 75 without rattling my teeth too badly. Since I seldom drive Beck over 60, I'm calling this one done!
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