My 40 Sedan has a front end shake at 60 mph and up, and it's driving me insane. Has absolutely brand new dropped axle, spindles, kingpins, spring, shocks, etc., etc., the wheels are balanced perfectly, the camber and caster are set correctly, and I have a pair of one year old (but in mint shape) fat white bias-ply firestones on there and they are toed-in 1/8". Is it the tires? Or am I missing something here? Does anybody else experience this with a similar setup? I am open to some ideas because if I get passed by one more bus i'm puttin the radials to her! <font color="black"> </font>
I'd recheck to tire balance.Usually when a wobble or shake comes in at a certain speed its balance.See if anyone has one of the old tire balancers that spins the wheel on the car.That way everything is getting checked. JimV
I am having the same problem with my ride 2slick. It already has radials on it so I doubt that will solve any problems. At about 55-60 the freakin' car shakes like me after a week long binge. The HAMB conscensus is to have the wheels spin balanced, which I will do as soon as I find someone locally that can do it. Since the frontend has been rebuilt and everything seems to be set-up correctly, I think I would concure with the balancing. And yes getting passed by buses does suck! I know too well.
I went down that road with my rod I built in the Philippines, balanced wheels several times, fitted solid bushes to everything, changed ride height, tried to fit a damper, and STILL never solved it. It could start at 10 mph, violent shaking of the wheels to and from, or at 70mph, or it would just not happen some days. Real frustrating after a ground up build .
More than likely an out-of round tire. Get the front end off the ground, set a jackstand with bent wire pointer - or whatever works - close to the tire and spin it by hand to check for roundness. Pay attention to wobble as well, you could have a bent wheel. An 1/8" or more out-of-round is too much. Might want to check your wheels as well. If the tire shop's been around for a while it may have one of the tire planing machines that can cut rubber off and bring the tire into perfect roundness. Out-of-round is a common bias-ply problem.
C9 nailed it. Common problem when I was a kid. I did have one once that a brake drum was out of balance. Rare I think. We solved it by spinning the wheels on the car and balancing that way. back to it C9 nailed it.
This may sound really dumb, but since I did it myself once... When you rebuilt the front end, did you grease everything? I rebuilt the front on my '54 Buick, and forgot to grease the front suspension--the thing was shaking and wobbling and all over the road. Remembered it wasn't greased, and the grease made it ride perfectly. Spindle nut tightened properly? Check those if the spin balance on the tires doesn't work. -Brad
I took the hup a couple miles down the road last week to get tires and an alignment. It drove like it was missing a wheel bearing (all new). Turns out I hadn't snugged the spindle nut tight enough.
Not too sure about bias plies (the new ones on my '54 are the first ones I've ridden on), but it sounds like a balance problem. Usually, if it's a tire issue, the problem will occur much sooner - around 20 -30 mph. A balance problem shows up around 50-60 mph. Make sure the shop that balanced the wheels had them centered on their machine properly. I've seen a bunch of wheels centered incorrectly that balanced out perfectly and shook like hell on the vehicle. See if you can find a shop that has a set of "Fingers" that fit into the lug holes on the balancer. You use a cone to center the wheel, then tighten these fingers down onto the wheel just like lug nuts - it guarantees that the wheel is centered on the machine. That's also a good time to check the tire for out-of-roundness. One more idea - see if you can find a shop near you that has a Hunter GSP machine. This machine measures road force and the newer machines measure side to side tire wobble - it checks centering and balance as well. Use this link: http://209.176.154.132/pub/search/findgsp9700.cfm Good luck, Jay
I've heard from a few guys I know that to stop the shimmy you need to get a dampner that attaches to the radius rod and the tie rod.There was a write up about this in rod and custom recently.It's just a small shock absorber. I got a kit from Socal for $35.I haven't installed it yet because I solved my problem. It was a loose steering arm where it attaches to the backing plate.The backing plate bolt was 1/16" to long. It would shimmy at 20 MPH. These guys told me I'll need it anyway because when you hit a bump at speed, with a straight axle, you'll get a violent shimmy that will require you to come to a complete stop. I'll wait and see what happens.
I experienced similiar wobbles etc at higher speeds. I dropped the tire pressure down substantially and the problem went away. ( 1936 front end, 5.60x15 cross plies, unsplit radius rods, cross steer) Having said that, I am not sure it is a real cure, as running lower tire pressure may now lead to uneven tire wear etc. Having said all of that, because my car( Model A roadster Hiboy) is so light, the wear may not be an issue. Adam F AKA PaintNoPrep
[ QUOTE ] These guys told me I'll need it anyway because when you hit a bump at speed, with a straight axle, you'll get a violent shimmy that will require you to come to a complete stop. [/ QUOTE ] The damper will simply mask a shimmy problem. You'd be better off to wait and see if it does shimmy. Then decide if you want to fix it or mask it and wait for it to come back when you least expect it. Speaking for me (32 roadster) and my friends full fendered 28 roadster, neither has a damper and neither shimmys. We've hit more than a few potholes at speed as well. Properly fitting kingpins, new tie rod ends, tight steering box, good shocks, proper alignment all add up to a couple of good handling cars. I've driven his and it drives almost as good as mine. Mine probably seems better cuz I'm used to it. Then again, he ain't got no big ol Buick engine like I have. Just a little ol 327 SBC. Gotta wonder though . . . how come the darned thing runs as hard as it does? And hangs right there in the rear view mirror....
Make sure the steering box is adjusted properly and centered on the "tight" part as the vehicle goes straight down the road. Also be sure NO deflection of the steering box mount can occur as force is applied to the steering box by the draglink. I've seen a couple of vehicles that had this problem and they were repaired just by "stiffening" things up a little. If stuff has room to move...it WILL move! Bill
A tremendous wealth of information here.Given by those with first hand experience. Much kudo's to the fellow's who have contributed to this thread.
Many thanks for all your responses. I should add that the shocks, wheels, and every nut and bolt in this front end is new and tight, however, I think the out of round tire may be the answer. I took the car down to the alignment shop to check it out and all toe, camber and caster are correct, save for a little more caster than I'd like (about 7 degrees). We balanced the wheels again and I noticed one tire seems out of round, but there is only one guy in town that shaves 'em and he will only do brand new tires, and he charges 40 bucks a tire. My stones are a year old with about 300 miles on them so he wont touch em. I also noticed that the frame has a bit of flex around the steering box when you turn the wheels while the car is stationary, so a boxing plate as suggested might help also. I am so glad that I am not the only guy who has problems with bias ply tires. Every set i've bought from Coker has given me grief. Anyway, thanks to all you Hambers for the solid and constructive input. That is what makes this great.
Mount a Steering dampner, new Mercedes and Audi's have them. So its nothing to be ashamed of. You can get a shiny one from So Cal. Or go to you favorite junkyard and look under a VW or Audi, i guess some of the new Anerican iron have them to. I have a WV on my Model A Roadster and have not had a shimmy since i mounted it. Its a 30 minut job to mount it if you have to make your mounts...
Ooops forgot an old fashion way, that is supposed to fix the shimmy can be to set a slight amount of toe out! Ive ony heard about this one and never tried it myself, the theory is the this should add some "preload" to the steering gear preventing the shimmy. Could be worth a try.....
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