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On-car spin balancer
Posted to Tool & Equipment Forum on 9/6/2014 96 Replies

Why use an on-car spin balancer…? (This was requested information)

In one sentence: Because nothing else compares. -- With the exception of a force balance computer balancer, no other type of balancer is as difficult to master. Once you have there is NOTHING that can't be balanced to perfection.

The on-car spin balancer is more accurate than a protractor, a bubble, or ANY kind of computer balancer. You just need to use your brain. Be smarter than the problem.

Where to start… Hmmm; background. I began using on-car balancers in 1972. I've balanced at least 40,000 tires using this method, many with the Hunter Tuner, fewer with the Alemite/Hunter strobe. In 1986 I stopped using both the tuner (not accurate enough) and the strobe. All the strobe does is help you to guess. I felt I no longer needed help guessing, after over 15,000 balances

Spin the wheel up to (60, 90, 120, 140 MPH) and you will find the harmonic point of shake. Usually at 55-70 MPH, but you'll possibly get a secondary vibration around 120-130 MPH. Very tense vibration at that speed. A computer balancer spins at a single RPM and has no harmonic sympathy. Larger tires will shake at 35-45 MPH

The question that any interested person would ask, is, "How do know where to put the weight, and how much weight should it be?" Thanks for asking…

When I feel the severity of the vibration I can make a very accurate guess on the weight needed. Let's say that my guess is one ounce. I put a one ounce weight at the valve stem. If the vibration remains the same, I'm about 90* off. If I move it 90* to the left and the vibration gets a lot worse, then the weight needs to be moved 180*. Make sense..?

If all of this sounds like a giant hassle and an old man's 'pipe dream,' I will meet you in Sacramento and rotate and balance four 16" tires, alloy or steel, faster than you will with a computer balancer and that vehicle will never come back for a tire vibration.

You may also consider this: I can get my balancer, in perfect working order, (I actually have two. Total investment, $300) for $500. Your computer will set you back at least times that much. My balancer never malfunctions or needs calibration.

I'm certain that the vast majority will poo-poo my assertions, but for the few who don't, feel free to ask any questions you may have. Also, bear in mind that on several hundred occasions, I've balanced tires that were previously balanced on the computer, usually several times. Like I said, I get zero come-backs.

I should mention at this point, I don't balance drive wheels. (I find it more troublesome) I balance the rears or fronts, as the case may be, then rotate them and use the spinner again. This isn't necessary, simply easier, faster and more accurate due to speed control. Some would argue that it is less accurate due to axle and hub imperfection, which is a somewhat worthy point. But you lose speed control, something I consider very important. Besides, any other type of balancer has no hub or flange centering capability.

The only person I've met who has done half as many on-car balances is my father. Even he never mastered the tuner and strobe less approach. I didn't do this until I was 28. Pop never used a spin balancer until he was 27. I'm pushing 58, so I've been doing it 'my way' for 30 years. Prior to this, I was using the tuner and/or strobe for 12 years. I'd have no problem explaining their use, either.

So make me a punching bag, again, or ask to be educated…

David Schaaf
Dave's Auto Repair
Elverta, California, USA

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