Posted by chriscase on Thursday, March 15, 2007 at 11:11:50 :
In Reply to: Re: The Solution To Singles On W500's.... posted by Marty on Wednesday, March 14, 2007 at 22:09:33 :
I've done tires, driveshafts, a 7,000 rpm shaper shaft, some other gismos.
After learning how to do on-the-car spin balancing with the mechanism that clamps onto the wheel, and using the cars engine to drive it to speed, I figured out how to do it on other stuff. Just assemble your machine, spin it up to speed, and feel the vibes. Shut her down, and add a test weight. Anydamn place at random. Spin again, feel the vibes (at the fender, or springs or chassis, close but safe. DO NOT wear loose clothing. DO NOT work in an altered state of awareness, like drinking or stressed. Or while daydreaming about Paris Hiltons...money). Move weight say 1/3 of the way around. Try again, If better move weight some more. If worse, move back some. It's a checker game. It should only take six or eight moves, max. maybe. When you have found the best location, try changing weight amount, plus or minus, until it is smoooth. Then, try shifting position some again.
On open differential vehicles, block the opposite wheel, jack up the one in question, (duh), and put it on a jack stand. Have your helper go 40 mph, that will be 80 on the wheel in question. Good vibrations then.
On lockers, you need to jack stand both sides, and remove the unbalanced side wheel.
On drive shafts, for a test weight, use a worm/screw-type hose clamp. Or two. The screw part acts as the weight. Then when it's good, replace the clamp(s) with a washer(s) welded to the shaft. Do both ends. Drive shafts spin at engine speed in top gear, so they do have enough speed to shake pretty good.
The 7,000rpm shaper was balanced with a longer set screw, 3/4 long instead of 5/16. Not much weight, but a little makes a big difference at high speed.
Tires only do 500-800 rpms, so are less critical.
On Marty's hub, he'll need to use a nut on a stud as a test weight. Maybe cut the nut in half so it is thinner/lighter? Then, for permanent, drill out some weight from the opposite side. I would clock the hub, and mark it for l/r so you don't get it off balance later. Perhaps Marty has an outside machinist that has done this to some contraption? Prop shafts maybe?
It is a checker game, but it works good, and versus $300 ????
I sure do hate the off-the-car tire balance of today. They seem to last about 5,000 miles and then shake badly. At that point I usually remove their weights, which were placed by voo-dooo anyway, and then it drives better for the rest of the tire's life. I seldom need to resort to the above method for my pick-ups. It's time for me to remove the weights on my daily driver. I think a church key works as the best lever.
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