Tremendous shimmy on front end?
 

On my 84 300sd i came over to Tampa Friday nite and at 65 mph I hit a short stretch of road and it felt like it was driving on a dirt road of washboard. I had to hold on to the steering wheel with both hands. I managed to get to my destination at a reduced speed. I climbed under the car but could not see anything broken. The car did not pull nor make any weird noises. No squeal from the brakes and we just recently has the sway bar repaired where it broke from the front. I have no tools with me and I assume I can drive the car back home (125 miles) at a reduced rate of speed. I am just trying to figure what should be replaced on the front end. The car has 250,000 and new tires so I know it is not an unbalanced situation. Any help will be appreciated.

I would probably bring it someplace and have the front suspension inspected to find out if it's safe to drive. I sounds like you broke something.

Is the shimmy only at a certain speed or is it all the time? At that age and with that many miles anything is possible. I would definitely have a closer look at all the front end components before driving it again.

I agree with getting someone who knows their onions to look at the front suspension - it might be worth your while looking on the wheel rims to see if there is a missing balance weight.

Check both sides of your wheels - sometimes when tyres are fitted weights are added on both sides of the wheel. (Well for a good balancing job that's often the case)

Otherwise your experience reminds me of a really old film "My Cousin Vinney" when they get this special sort of mud in their tyres... (excuse me if you haven't seen it - and don't worry your life is still complete having not seen it)

Classic movie, here's the clip:

http://www.youtube.com/watch?v=nYJEyToSRtE

Have you got to any smooth pavement yet, where you can try it, to see if it still has the shimmy troubles or not?

I just wanted to throw out there a couple of things you might want to check. You can check the lug nuts on the tires. I have had them be loose after new tires installed. Tech gets distracted or whatever and forgets to cinch them up good. Also, check the pressure in the front tires. I know on the ones I owned a low tire in front will make a wild shaky wheel on the ones I had going over rough pavement.

Wheel lugs are tight. Tire pressure was checked on monday and corrected cold. Driven on smooth pavement up to 50 mph and no shimmy. Its New Years day and no one is open. I have no choice but to drive back to the east coast at less than 55 mph and see what happens. I have 100 mile range towing so if I find that it is undriveable I will have to have it towed. If anything is broke I think I would have seen or felt it when I got under the front end. I was driving on the FL tpke at 70 mph with no problem. That is what is perplexing me.

Broken belt inside a tire?
Bent alloy rim?

I'd at least jack it up and check the play in each tire 12/6 and 9/3. to see if the play is the same.

Drove home 145 miles at 55 mph or less. No vibration outside of small one in steering wheel. Took it into my mechanic and they put it on a lift. They checked the ball joints and there mechanic said that was the problem. They did both sides and aligned there work and rebalanced the front tires just to be safe. The owner took it out and had no problems. I drove it and got up to 80 mph and it was smooth as could be. Thank you for your responses.

congratulations,my car is in need of new ball joints aswell,but i havent noticed any shimmy in front end,i quess all cars act different,the ussual suspect is an off balanced wheel or broken steel belt in tire,glad you got it fixed before anything bad happened.