VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1916-1922 - Model 490 Stearing problem

On my 1916 490 wrile driving down the road if I hit a bump the front end shakes uncontrolably. I have to stop completely and start again. I tightened up the king pins but now the stearing is really tight while setting still or barely moving. What am I doing or not doing correctly?

I had that problem with my '28 Canopy Express.

I found that the cotter pin had dropped out in one of my tie rod ends, thus causing the threaded end cap to start backing out and thus, was not clamping onto the ball well. I tightened up the end cap, put in a new cotter pin, and it has not done the death shake since.

Check to see that all the tie rod connections are as they should be.

Dean

Is there any type of friction damper or shock absorber on the front axle of a 490? If so, that might be part of the problem.

Some of us who have experienced the infamous “Chevy shimmy” have been able to stop it by controlling the front axle oscillations better. I agree that about the only way to stop it is to slow down. When you hit the brakes the front end moves down which tends to stop the front axle oscillations.

Chevy uses what I call a “relay” steering linkage on their solid front axle cars. The steering gear moves the pitman arm which is connect to one front wheel spindle. The other front wheel steers because it is connected to that wheel.

When you hit a bump and the axle moves up, the front wheel connected to the pitman arm steers slightly which also steers the other wheel in the same direction. When the axle returns to normal position that steering action is reversed.

If the axle continues to move up and down with no control that creates the “shimmy”.

Thanks for the information, not sure I understand it all but I will check things out. Should I loosen the king pin nuts slightly or not?

Hi Ron,

Sorry that I am not familiar at all with the 490.

Did tightening the king pin nuts help the shimmy?

I would consider loosening them some and try to find the "sweet spot". You also might determine if you tightened the king pins so tight that it is hiding the fact that the pin and bushings are worn.

OK that is a thought ,they may be worn Thanks

On the early 1916 Chevrolet 490 cars, they used a duplex spring (two spring assemblies attached to the top and bottom of the front axle). I read these cars would sometimes have a "shimmy". Chevrolet replaced the springs on the later 1916 models with a single spring leaf assembly to eliminate the shimmy. Another thought would be you may have worn parts. If you push from side to side on the front wheel and have just a slight amount of motion with the spindle, you could have worn bushings. If the king pins have motion, you may have a worn axle.

As some have mentioned you probably have worn parts. After checking all those possible parts several things to think of is your alignment. You would want both tires toed in a little (not much just a little) then also you would want your camber adjusted to where the bottoms of the tires are in a little more then the top. This is also done on Model T's to help with the death wobble.

Hi Ron,

I have a 1916 Chevrolet Roadster with the early Duplex front springs. When I restored this car 22 + years ago everything was brand new and the thing still developed wheel shimmy to the point where it shook the car so bad I had to stop and start again. I spent years chasing the problem with everything from tire pressure to over tightening the steering parts to changing all the steering angles and axles and wedges all of which failed to stop the problem.
In the end I purchased a steering damper kit from Snyders T & A Parts and it solved the problem to a point where it can now be drive with out fear of the horrendous wheel wobble shake.
I think the problem with the very early 1916 pre 40,000 cars is the top and bottom Duplex spring works against itself. The chassis wall thickness is also thinner than the later in the year cars with the revised front spring set up. It may also be worse because of the steering box mounted on the wooden firewall makes the shacking go thru the whole body of the car and not a nice feeling at any speed.
Hope you get the problem solved with the steering damper kit and start to enjoy the car.

Thanks so much for all the information,I had no idea it may be a design problem. I live close to Snyders Antique Ford store and have bought parts from them. I will try the stearing damper.

I strongly recommend that you confirm that the steering system parts are in good working condition. The steering damper might hide a problem.

Thanks I will check steering parts first.

I put a steering damper on my 16 Chevy and that solved the shimmy. However, the turning radius is less than it should be.

If I need to replace the king pins or bushings does anyone make them. I looked at the Filling station and they dont go that far back. I have heard that early manufactuers made parts for several car companys, not sure if this is true or not. Such as front axels.

If you need king pins and bushings, you can purchase them from model T parts suppliers. You will need a reamer tool to align the bushings and allow the king pins to fit properly. If the axle is damaged, it would be best to repair it.

OK Snyders Antique Ford parts is 20 miles from me, may be able to match parts there if needed.

I put new wheel bearings and king pins in my 490 ,model t parts work and the reamer size is the same. Runs perfect down the road.