the frount end shimmed

I went to Vegas last weekend, about 400 miles round trip, in the 41' found out that at about 60 mph the frount end shimmed. Getting ready for the trip I had the wheels balanced to avoid such difficulties. The car is stock, I have replaced the kingpins is all. What or where should I look next to solve this symptom.

 

Check wheel bearing preload, tie rod ends, pitman arm ends, etc.. Also check the spring shackle bushings. Every thing about the front end should be nice and snug. If every thing else is in good order make certain that the front end is properly aligned and the the tires are truely round. One other thing is too many old car folks don't grease things properly. Afraid to create a mess or something I guess.

 

Are your tires old? that was my problem. they were way out of round.

 

If as said above all the front end componets are good ,and it only happens at a certain speed check your toe in/out.

 

Also what tire pressure are you running in the front? Too high a pressure will also cause a shimmy because the tires are bouncing like a basketball.

 

Can't tell from your small avatar picture but are the front and rear tires the same size? If so, swap fronts to back and see what happens. You might want to get a tire off the ground and put a paint stick or dial indicator against the rim and spin it to see how true it is. Shocks can also not dampen out the oscillations if they are worn out.

Try playing wth toe in and toe out, and check your steering box for sloppiness. If there is a way to clear the cross steering setup fab up a bracket to mount a SoCal stabilizer on one of the wishbone sides, that will certainly help too.

Don

 

That could be caused by any of the above suggested things and it becomes a process of elimination from there.

Is it a shimmy as in the steering wheel wanting to rock back and forth a bit or is it a vibration where you see the hood or a fender shake a bit at a certain speed?

Running the car for a ways and going back to the shop and jacking up each front tire and spinning the tire by hand while having something sitting in front of the tread as a reference will tell you if a tire is out of round or not. They need to be warmed up before you do it though as some get a bit of a flat spot from sitting for a while. Check the tread for any breaks in the tire cord at the same time.

Set the tires on some ramps and have a helper move the steering wheel back and forth a bit while you watch to see if there is any slack in the rod ends in the steering.

Look at the spring bushings and other suspension parts to see if there is any obvious wear in them.

How are the shocks? I've driven down the road beside cars that had the tires come 4 inches off the pavement due to bad shocks and or out of balance tires.

If it was ok for a number of miles into the trip and suddenly started you might have lost a weight of one of the rims.

 

Like Don said... Maybe one of the steering stabilizers would also help. Put one on the roadster and solved my 'death wobble" problems...

 

Sounds like could use a good rebalance job

 

Thanks for all the info; rims and tires are new and I had them balanced twice, once when I had them installed and once after I felt the shimmy. I ordered new tie rod ends, Steering Drag Link Assembly - Bent End Type - Ford Passenger, Tie Rod End Cup Set, Pittman Steering Arm - Ford Passenger

After I install the new parts I'll try to find a front end shop that can a-line and correct toe. The shocks are original I'll try to put new fluid in them if that doesn't work I'll try to replace them.

 

Don't know if it pertains but in '06 the front end shimmied on scarliner's coupe @ a specific speed and then would settle out. We discovered that it had a broken leaf. Might be worth lookin into.