Strange vibration

Brother Hesekiel

Brother Hesekiel

Senior Member
About a week ago, I fired up the A, drove it slowly down my street, then turned onto the main street, accelerated gently, and the entire front end started to vibrate like the wheels would be falling off any second. I stopped, checked everything, found nothing wrong, drove off again, and it was fine, didn't happen again.

Past Friday, the same thing happened. Shortly after I turned onto the main street, the front end/wheels (?) started to shake violently, so I stopped, took a deep breath, started again, and it was fine.

I drove the car all Easter weekend, including a lenghty high speed run in overdrive, and it was running like a Swiss watch. Drove it this morning and it ran fine. This afternoon I started it again, drove down my street, turned onto the main street, and it started to vibrate violently. I didn't stop, just slowed down to about 5mph, then accelerated again, and it ran fine the rest of the day.

I'm flabbergasted. What could possibly cause this phenomenon?
 
Yo, Bro,
When I got Vermin, it would start a bad old fashioned shimmy,ONLY in front of Bill Jones house, tried it 4 times, & it shimmied every time. There was a funny spot of undulating pavement that set it off. I had 1 drag link end with slop in it. Bet there's some "funny" spot in the pavement , where you pull on to Main St! Old fashioned shimmy is almost always caused by play, somewhere in the steering linkage. I had to come to a COMPLETE stop, to stop the shimmy. With weight on the wheels, have someone turn the steering wheel back & forth FIRMLY & you'll find where the SLOP is.---Bill W.
 
Check the tie rod ends and the drag link but most of all, check the toe in. I had one that did exactly as you describe and the wheels were not aligned correctly. Toe in should be 1/8".
 
Sounds like a good question for Click and Clack.:D

My 29 Chevy does the same thing, but I haven't looked into it yet.
The temporary front axle I put on my 28 Phaeton has king pins and bushing so worn that I can shake the tops of the wheels in and out an inch and a half, and yet it has never had a hint of shimmy.

There is a 31 Town Sedan in our club that I followed on a day trip and his car had the shimmy, but only on the left side. I found a loose tie rod on the left side.

My 1971 Scout never had a shimmy until I installed factory chrome reverse wheels with fat tires. I took them back off and put the other wheels and tires back on, but the shimmy continued. I still haven't figured that one out.

I agree with James that the first thing I'd check is loose steering rods and toe in. Also check the steering shaft to pitman arm for tightness. That bolt needs to be very tight.
 
This vibratory behavior can happen by flat spots developing in the tire treads. After some driving, the flat spots go away, and so does the vibration. However, I also suspect that the front suspension on your Model A has too much play and perhaps needs a toe-in adjustment.

Go back to basics and check all of the joints in the front suspension.
 
A shimmy can be/is dangerous. As the fellas said, there is something loose. Check everything in the front end from the steering box to the wheel bearings and everything[ including the radius ball] in between.
 
You must log in or register to reply here.
Back
Top