Violent Car vibration @ 50mph!
 

I have a 1982 300SD that runs really good, until you hit 50mph then the car vibrates VIOLENTLY. The tires have been balanced and I was thinking maybe rotors but the car brakes fine with no wobble. Its only when you hit 50mph, and it feels like the wheel just popped off or something. :mad:

Any ideas? :confused:

More details please...my crystal ball has a bad monovalve!
 

How fast is the vibration? Is it wheel speed? Is it driveline speed? Can you tell where it is coming from? Front, back or middle? Left or right?

One thing that occurs to me might cause a vibration to suddenly appear is a bad center driveshaft support. The rubber in the support might have failed.

Re: More details please...my crystal ball has a bad monovalve!
 

its REALLY fast side-to-side vibration in the front. I HAVE to slow down I can't continue like that so I need to have this fix or else I wont be able to drive the freeway.

Sound like a SERIOUS problem with a steering component (most likely a tie rod end, drag link or steering arm).

Seek professional help immediately (at speeds under 50 mph!).

So this feeling is felt in the Steering Wheel ? Or in the car in general ? Can you tell if it feels side to side or up and down ? Or all directions.....

Another question.... does it go away at speeds above 50-60 mph?

Generally, speed sensitive wobble is wheel ballancing or mismatched tires - but you said tires were ballanced.

Sounds like a pretty serious problem there, drive it the least you can until you get it fixed which should be immediately. Are there any lumps in the tire's sidewalls? Sometimes a belt will get weak or give out and make a HORRIBLE vibration in the vehicle. Did this just happen suddenly one day or has it been progressing slowly?

I have an annoying shake where I can watch my hoodstar shake side to side as I'm going over 55, it comes and goes at certain speeds. I'm going to repaint the rims on my 84 then get them balanced, also going to put on a new inner/outer tierod and upper ball joint. I have a feeling my case is just wheel balancing.

does the vibration cease or diminish if you were to apply the brakes? apply the brakes while maintaining the 50 mph threshold?

The shaking doesn't stop until to de-acel. about 10-20mph and the WHOLE front end shakes not just the hood. The steering wheel, hood, wheels, everything. As far as if the speeds go away above 50-60, I dont know...there is no way I can get the car above those speeds I would end up losing control of the car. Im going to go have it checked out today. :mad:

Well the hood by itself shouldn't shake, my point was if I focused on the road while looking through or around the emblem I can see the front end of my car shaking as I'm driving down the road. My whole front shakes as well, including steering wheel. Mine has different 'resonances' at about 53, 67, and 74 where it gets worse, above and below those speeds it isn't as bad or noticeable at all sometimes. Anyway good luck and keep us posted.

There are pins that are called eccentric, if they have wear they will cause this problem. I know this because of my wifes car did the same thing.


Jim

Shaking
 

Before I had enoough sense to get a Mercedes diesel, I had a Ford Taurus and they broke engine mounts faster than you can say Pooh!. The indication that they were gone was very rough shifts and lots of vibration. Both always broke and hence the engine was being held in by only the transmission mount, very dangerous cars.

Check out the engine mounts, as Mercedes mounts do break but only once in a lifetime.

ben

flex disk
 

could be a worn out flex disk coupler.. I thin there is one in the front and one on the rear of the driveshaft

had same prob with my 1990 car would shake at about 50-60mph and shifter would shake too.

replaced both flex disk and problem was cured..

hope that is all it is..

good luck