Hints on solving front end 'wobble'..

Tom in TN

Tom in TN

Senior Member
'34 coupe, with fresh front end parts and a steering box redone by Josh Mills...

Crusing along the blvd and go over a railroad track...front wheels start flopping side to side so bad the car almost stops. - after shaking my kidneys loose...doesn't happen every time, but if I don't have the wheel turned so as to load it to one side- look out.

Toe-in as about 1/16th. Caster/camber is factory.

Any likely suspects from your experience?
 
The current issue of Rod and Custom (August 2014) has an excellent article by Chris Shelton on the causes and fixes of the dreaded "shimmy" that old Fords sometime experience. Major contributor is tires. Check it out.
 
I had the same scarry wobble when I first built my model A. I tighted the spring on the tie rod ends and it never happen, Been 8 yr's. Walt
 
It is almost always caused by play / something lose
　
Whenever I take my off (here) topic rig off road and get back on road I need to stop and torque down the shackle bolts or it will death wobble like crazy.
It can be something as simple as that
 
I too have had the death wobble recently after finishing my 34 pickup project ( well almost finished).
I did the following to fix it and its gone.
Tightened up front spring shackle bolts
Tightened each spring loaded tie rod end and drag link ends. These need to have the internal spring at least 25% compressed . Also mine had all new innards.
Re adjusted steering box for end float on sector shaft and for play in worm.
Now it steers like a 34 truck !
 

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Thanks ya'll...probably need to tighten the drag link ends a bit more, but everything else is good...running diamondback radials, spun balanced. Tie rods are Heim joints.
 
I prefer spin balancing on the car but the computer balancer can detect something about the rims. The tech took my wheels off the balancer, broke them down and turned the tires to a different position on the rims. Back on the balancer it took less weight. Still don't know what cured my problem but at least its fixed.
 
There are a number of possible causes for your shimmy, If you go to the HAMB section of Jalopy Journal there are a couple good posts on solutions or trouble shooting your issue. The first area to examine is loose parts. The second area is to make sure that the front spindles are square to the axle and the axle is square to the frame. It is easy to have the spindles slightly adjusted in a skew position, this excites a shimmy as the tires try to center after hitting an obstruction. Also make sure the tires have equal air pressure and you should not have over 6* caster adjusted in your axle set up.
 
Had a similar situation on my F-500. Truck shop wanted to put new kingpin bushings in. I took it a tire shop & the guy found one of the rims bent. WE replace that & it never shimmied or wobbled again. I have sold the truck & have a set of bushings now for a paper weight.:(
 

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I had that same thing happen in my '34. I tightened my tie rod ends, by 1/2 turn, and it hasn't happened, since. That was, at least, twenty years ago.
MIKE :) (mikeburch)
 
When everything else fails....don't fight with physics, much like Mother nature. There are a lot of trucks out there with solid axles that have a 'Steering Dampener'. Guess the design engineers could not figure out why on the same vehicle, one had shimmy and the other not. Even had one on my old '75 Eldorado...many moons ago. Also, 50 years ago now, could not get rid of the same railroad track shimmy, no matter what I did. Guy at the auto parts then, when we had knowledgeable people behind the counter, sold me a Volkswagen steering dampener. Problem solved....it's still on the car and driven close to 100,000 miles. All the 'Hot Rod' shops sell them now.....wonder why??...no questions asked...IT WORKS, and you will never feel that it's there. Robert
 
Set the toe in try 1/8 in maybe a little more. Jack up one tire scribe a line around it as you spin it. Set it down do the same to the other one. Roll the car back and fort a bit to settle the suspension ( some spray paint on the tires first will make the line harder to erase) get the distance between the lines at the back of the tires evenly at the spindle height then check at the front it should be 1/8 maybe a little less press out on the front the insides of the tires check again tighten up the toe in to an 1/8th in as the front end tends to spread apart as you go down the road. This will even compensate for some play in the parts. I found correct toe in stops the death wobble. Try this first might save some money. MW
 
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