VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 vibration in the wheels

Hello,

My 1930 4-door sedan sometimes has vibrations in the front wheels. This happens at a certain speed, when the second is used and the speed is too slow to shift to the third gear. Last month I met a person with the same car from 1931 and he has the same problem. Is this a well known problem? I can't find anything on the forum. Does anyone know a solution? Add a steering damper?

Thank you for your help.

PS : the king pins has been replaced and I don't see any play in the steering

Are you experiencing wobbling or uncontrolled movement side to side of the front wheels. Many call that "death wobble" Do your front springs have wedges between the spring and axle? Increasing air pressure to 35 psig or higher, increasing the toe-in, tightening the tie rod ends on the center rod (between the front wheels) can all help. Adding a steering damper can be a big help in eliminating the wobble.

Thank you for your advices, Chipper. I will try all of them one by one.
For the steering damper, do you know a model I could use ?

Hi Edmond,

Chipper’s suggestions are on target. Eliminating any free-play or slop is a key factor. This includes kingpins, steering gear adjustments, wheel balance, and even wheel bearings.

There are some cases when the “Chevy shimmy” has been eliminated by making sure the front shock absorbers are working properly. When the front axle moves up and down it actually steers the car by a small amount. If that up and down motion is not controlled it creates steering shimmy.

In some cases a steering damper is needed.

You may want to get the front wheel alignment checked after eliminating all possible free play.I found the following data in my 1936 Chilton Flat Rate Manual for 1930 AD,1931 AE & 1932 BA models:

Caster 2 1/4 degrees positive (car empty,full petrol tank),Camber 1 1/2 degrees positive,Toe-in 3/32" - 1/8"

Funny you mention air pressure. My restored 31’ special sedan has the whole front end new, bearings tightened as they should be, tie rod ends tight, etc. My car loves to follow any crown or dip in the road so at times, depending on the roads condition, it drives very squirrelly. I have BF Goodrich WW tires on the car and was running them at 32# pressure. Frustrated with the unwanted side to side, I checked everything over again including alignment as I mad my own spring loaded toe in gauge with chains and all. So with everything in correct spec, I decided to air the tires up more increasing them to 35# or as a friend said, 10% more. Well, what a difference in the car now. The unwanted side to side is virtually gone. Now I’m tempted to increase pressure another couple pounds and see if there’s any more difference.

Chipper, where can those axle wedges be bought? This 30’ I’m working on was in tough shape with the u bolts loose or rotted off to the point both axles were loose on the perches. The front axle had one wedge pad on one side and I believe the other side fell out.

Ted,
Most places that have done front end alignments on straight axle trucks will have wedges. They also may be available from companies that supply front suspension parts. I am thinking 2 or 3 deg. is what originally was used. Can look up specs if you can't find them. I did a quick look and didn't find them so a deeper dig will be necessary.

Try Rare Parts in Stockton, CA.. They have a tremendous inventory of suspension parts. Here's their web address: https://rareparts.com/

Cheers, Dean

Thanks guys. We’re the shims installed in all cars from the factory or just when some handling issues came up. My own 31’ doesn’t have them and most the cars I’ve worked on haven’t had them either.

I think all straight axle vehicles use tapered shims to set the correct caster. If you can't find them locally give Donovan Spring in Londonderry N.H. (603-669-2250) a call. Ask for the spring shop as they also have an equipment division.

Thanks steve

preasure increased from 29 to 35 psi. test next week ...

Hello
pressure increase tested yesterday, the problem persists ....

My 29 didn't have tapered shims and it steers straight. I believe I have close to 40 pounds in the narrow tires. I set the toe in close to 1/8".