Front end shimmy

Will N

Will N

Well-known member
Now that I'm getting a little more practiced and taking her out on the open road, I find that I get a fairly big front end shimmy when I get her over 30 mph. I don't have a speedo, but I think 30 mph is right because once I took my GPS with me to see how fast I was going, and at the 30mph I was going at the time, it did not shimmy. (I do have all the parts for the speedo save for the cable- that's a to-do job.)

I put new roller bearings in over the winter because one of the old ball bearing cups was cracked. The bearings are adjusted correctly. There is no slop in the king pins. The wheel spokes are tight. The tie rod ends are tight, as well as the drag link end. The radius rod ball had some play in it. I installed a fender washer that I cupped with a ball peen hammer and reinstalled the cap. Seems like that took up the play. But I still have the shimmy- it didn't get any better.

The wheels are out of balance. If you jack it up, and spin the wheel, it always stops with the same point of the wheel at the bottom. So I'm surmising that the out of balance wheels are the cause of the shimmy. I've got the original wooden wheels with non-demountable clincher rims. How do you guys deal with balancing these wheels?
 
Will

Did you do the front end alignment after replacing the front wheel bearings from ball to roller?

That may be the source of the higher speed shimmy. And also are both front tires the same pressure?

A low speed shimmy includes all of those things you did so far, and sometimes the steering gear cluster needs attention or the bushing in the steering bracket at the frame.

Best to check out the front axle(pitch back of the axle, it should be 5 1/2 degrees back pitch) You may need to bend the axle back to get that pitch.

Then check the toe in...or 'gather' as Ford called it, you measure and then adjust the length of the tie rod aat the spindle yoke to get the tire/wheel to the correct setting.
 

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I did not check the toe in. I will do that, but it does track nice and true with very little steering correction needed, so I don't think the toe in is off by too much.

Has anyone used those Dyna Beads that are in the Langs catalog? You put them in the tube, and they supposedly automatically balance the wheel.
 
I know two people that use them and swear by them. Personaly, I remain skeptical. Be advised that the wheel will still stop at wherever the beads happen to be laying in the tube if you spin it while it's jacked up. You have to be moving at speed for them to distribute throughout the tube. I have questioned both these people as to wether they get a low speed bumping action until the beads distribute and have gotten vague answers hence my skeptisism. My speeds are generally low and I won't trade a high speed bump for a low one. My 2 cents only.
 
Charlie, yeah, that's what I figured. Those things have got to settle out when you stop and you'd get a worse wobble until (if) they spread themselves out again. What if they clot and never spread out, then you're worse off then you were before.

I don't think you can use the normal lead weights to balance the wheel, as there doesn't seem to be a place to attach them on the clincher rim. Would you maybe screw a weight of some sort into the felloe?

Franklin, thanks for the tip. When I had the car jacked up to put the washer in the radius ball socket, the axle dropped all the way down and the shackels did not bind.
 
Will,

I have a 1911 Buick that is capable of cruising at 50+ & its wood felloe wheels are balanced using stick on lead weights meant for mag wheels. They seem to stay on & if you put them on the inside they are not too noticeable. They do make a difference.

B.F. Goodrich tires seem to be a better built tire as well. The stock size on this car is 30 X 3/12. It has 31 X 4 tires now which ride well & add a tiny bit of speed.

I do think you will find your shimmy is toe in or maybe camber related.

Beware if you have enough camber to operate well it makes the car tricky to back up at any speed. I have a 14 T that goes forward like a modern car but is dangerous in reverse. It has close to 10 degrees camber.
 

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Is your pitman arm tight on the steering shaft? Steering wheel loose on shaft or excess play in the gears at the top, sounds as if you have covered the other trouble spots. On wire wheels lead wire wrapped on the spoke works for balance, lol. Scotty
 
Well, I picked up the stick on weights this last week. Finally got around to checking the toe-in. It's fine. But while I had it up on the jacks, I took another look at all the joints. I found that my kingpins are not as tight as I first thought, and the passenger side tie rod end has play as well. So these will be my next project. However, I balanced the wheels as best as I could by loosening the bearings and spinning the wheels to see where they bottomed out. Had to use a lot of the weights (three strips!) to counteract them always stopping in the same place. Took her out for a spin, got her up to speed, and no more shimmy!
 
Also make sure the king pins are tight ( torqued) as well. They need some tension up and down to prevent some low speed shimmy ...
 
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