wobbling at low speeds

Billy 1931 Model A

Billy 1931 Model A

Member
My Roadster has a wobble around 20 MPH, which goes away at higher and lower speeds. It also goes away when I steer a bit left or right. There's a bit of play in the steering wheel.

Does this sound like a steering adjustment is needed, or is this simply how a 90 year old car behaves?

Thanks for your advice.
 
How much steering wheel play ? Shouldn't be much more than an inch. The box can be adjusted.
How much run-out on the front wheels ? Shouldn't be more than 1/16-1/8". When checking the runout of the wheels take a good look at the tires.
 
Could be out of balance tires, or death wobble. Death wobble can be caused by a whole slew of issues. Do a forum search on Death Wobble. Mine was caused by too much "toe in".

You probably have a two tooth steering box. This link is helpful to check and adjust.
http://modelabasics.com/twoTooth.htm
 
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Since the picture in your avatar is not a Roadster, it would help to know the year of the Roadster and whether it has a 7tooth steering box (28/29) or a 2tooth steering box (30/31).
 
Check that the front wheel bearings are properly adjusted. Tighten the nuts up slightly tight, then back them off a little. The wheel should turn freely without binding but should have no thrust clearance. Also check for worn kingpins. Jack the front end up so the wheels clear the ground. Grab the wheel at the 12 and 6 O'clock position and try to rock it back and forth in and out, top to bottom. There should be no appreciable movement. If there is it means the bushings are worn.

Tom Endy
 
Steering must be tight. Correct any looseness. Have someone turn the steering wheel back and forth while you observe the steering action.

Check the balance of the front tires by jacking up the front end and loosening up the brakes and bearings. (Record the clicks of the brakes so that they can be set back to the proper adjustment and record how many cotter positions the bearing nut is moved. Half a turn should be sufficient.) Rotate the tire and let it coast to a stop. Do this a few times and if it always stops at the same position, add stick-on lead balance weights at the top until it stops at random places.

Return the brake adjustments to the original position. Return the nut to the original position and check to see that there is no noticeable play in the bearing. If there is then tighten it one cotter position at a time until any play is gone. Most people tighten the nut until there is some drag on the bearing and then loosen it up one cotter key position. Mark the drum and wheel on each side so that the wheel will be replaced in the exact position if it is removed. (The brake drum is not balanced so that the drum, tire, and wheel have to be balanced as a set.)

An unbalanced tire/wheel will have a natural frequency (rpm) at about 20 miles per hour where the unbalance will be felt the most. At lower and higher speeds the unbalance will be felt less.

The steering must also be aligned properly. Check the tow-in and caster. The tow-in is adjustable but the caster is not. There should be 1/16 to 3/32 inch tow-in at the tire tread.

Check the shocks. Jump on the fender. The car should not bounce when you do this. Adjust the shocks or replace them if needed.
 
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I did all of the above on a newly restored car and the problem remained. I remove the rubber ball at the rear of the wishbone, put in a couple of sims to take up a bit of slack in the old clamp and all was well.
 
I would jack up the front of the car, then turn the wheel and actually grab each wheel up front and see if you can find where the problem is. It should be much more prevelent with the whls up in the air.
 
Ken Bolton has a good input. Everything in the front end must be tight with no sloppiness or flexibility. I don't have any experience with the rubber ball, but can imagine that it could also change the caster.
 
Start at the wheel bearings and go through the entire steering system looking for worn out balls and cups in every joint. My Vickey had worn bushings in the steering box. After a box rebuild and all joints refurbed no more "death wobble".
 
I had the wobble so I checked everything except for the part that the pitman
arm bolts to the box. It always looked tight, but it made a squeak at various
times turning the wheel. Guess what? I tightened up the bolt & nut and
now, so far no squeaking, no wobble yet.
 
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