Chevrolet C60s - Front Wheel "shimmy"

[Lynn Eades]

Phil, the wheels are forged and I think that "eccentric" extra bit, is commonplace. The military Dodge rim was factory balanced. (welded on steel weight) I assume CMP wheels were as well.
I noticed the brake drum is not running exactly true. An out of round drum can be a culprit.

[Andy Beevers]

John,
such a small world at times.
Somebody else reccomended Jones, called them this morning, in the post now, should be here tomorrow.
I have already got a bush puller and replacer so good on that thank you.
I have ordered an H10 adjustable reamer which should allow for what I need.

Phil, excellent video, however once you start on you tube difficult to stop, liked the HUP going out in the snow too.
Once those wheels start to go shimmy, it takes everything with it.
I did notice a little movement on the pitman arm draglink, (tighten screw all the way in, then back off half turn, fill with grease, sorry sucking eggs etc.) but from that view the temptation is to say the wheels start the shimmy and it just gets bigger till centrifugal force wins and pulls the shimmy back out like a gyroscope.

I will still follow the engineering principal of 1 item at a time, then I will know.
So, will get the springs done, then balance the wheels, and try to post a video like you have done, might take longer for me to do that than strip the truck!

Should be out for a roadtest this coming weekend, if all goes as promised.

[Andy Beevers]

Phil,
Some other points,
truck sounds real good, accelerates well, gear changes, wow, so smooth and quiet.

The following are random thoughts that may get me somewhere, or not.
I am tempted to try something a bit different.
What if a weight was placed, of a significant size, on the wheel and then run again. If the shimmy was worse or better, then wheel/drum imbalance is the cause. It is a theory, if it can be made worse, then the opposite should make it better.

I have a box of stick on weights, will try, 100g strips, a couple should do something.
Then using the logic of the on car balancer, using the tyre valve as a starting point, should be able to do on road balancing. Problem though, is one wheel at a time is the best way, some more thought perhaps.
Not overly keen on testing one wheel at a time on axle stands, the way it shakes could be a bit more excitement than I need.

[motto (RIP)]

Originally Posted by Lynn Eades

Phil, the wheels are forged and I think that "eccentric" extra bit, is commonplace. The military Dodge rim was factory balanced. (welded on steel weight) I assume CMP wheels were as well.

The welded steel weights on the 3/4 ton Dodge wheels (I think supplied by Budd) seem to be a standard weight in a standard position to compensate for the valve stem cutout. I suspect they were not individually balanced though I have not compared wheels to confirm this. It would be an oddity if they were as I don't know of ex factory weights on Jeep or GMC/Stude wheels etc.

David

[Lang]

These balance beads work absolutely wonderfully. They take into account any unbalance caused by bearings, drum weight, wheel weight and tyre weight and even slightly out of round.

The physics behind them is very complex but they are very widely used, even on 200mph race cars. They are relatively cheap and many brands.

[Tony Smith]

Do they work with inner tubes? I understood them to used by putting a handful inside tubeless tyres when fitting to the rim. Would you have to remove the valve from the inner tube stem and feed in each bead one by one through the stem?

[Lang]

Tony

You can get small size balls to feed into a tube stem.

I saw a set of tyres (tires) fitted in USA for a Dodge WC and the kit came with the balls and a little funnel arrangement. Took some time and a little jiggling but the result was perfect.

You are right about the tubeless tyres, just throw in the bag, which quickly disintegrates to release the balls when fitting the tyre to the rim.

There is also heavy liquid to do the same job on the market which I presume would be easier for tubes. Motorcycles use this a lot.

Antique and Classic Car owners have discovered Dyna Beads®!
Classic Car and Antique Automobile tires, whether tube or tubeless, need Dyna Beads®. This long era of automobiles and the styles of tires that were used back then lend themselves perfectly to using Dyna Beads for tire balancing.

If you look at this video at around 2.25 minutes you will see a valve stem filling system.

https://www.youtube.com/watch?v=z4h0H7ycIBg

Lang

[Phil Waterman]

Hi

Simple caution about using Dyna Beads, be sure to use good metal value stem caps. Reason I say this is that years ago had a version of the beads put in the tires of my C60S tires by a heavy truck tire shop. No problem airing up the tires but later after adjusting air pressure down the the stem valves would not always seal complete. Blow a little air in problem would go away. Replaced the stem valves, same issue bleed air out valves would slow leak, quick blast of air in they sealed again. As a precaution replaced all the plastic value caps with good metal ones.

Now as to did the beads balance the tires no. These were used 11:00x20 military tires probably 50% tread cronic out of balance in the end replacement was the only fix.

Cheers

[Bob Carriere]

Tried twice getting the wheel balanced at commercial truck shops.....one look at the wheel/1050x16 none were interested citing various reason...... will not fit there machine...... we do not spin balance on the truck....... a few ounces will not mean much against the mass of the tire wheel combination.

Suggested moving the tired in different location and play with tire pressure snd that resolved 90 of the problems.......Shimmies now at very top speed of 44 or 45 MPH and since I find that speed dcsry the more comfortable 35 mph has no shimmy.

Even a guy in the States that had 900x16 (power wagon)shaved and claims they are now smooth as silk BUT tires had to be marked for corner location and same bolt pattern for each wheel

Considering beads now.......

What experience do others have had........

I have a new spare set of Michelin 900x16 to try out next SUmmer.

Cheers