126 vibration
 

Hi all,
I've been trying to fix a vibration in my 84 500SEL for quite some time now. The vibration is first felt at about 20 mpg. It is just barely detectable. At about 40 mph it gets a little more pronounced. and then at 75 to85 mph it is bad. So far the the driveshaft has been replaced (used one from an 89 420SEL). the rubber flex joints (new), center support bearing and carrier(new) with no change. I was really shocked there was no change since the carier bearing and rubber suport were shot and the flex disk were full of cracks. Of course the tires hav been balanced on more than one ocasion and rotated more than ounce with no change. I finally got serious about this and set the car on jack stands(actually on a lift with jack stands under the lower rear supension arms) and ran the car at 20 mph and could feel the vibration. Then at 40 mph and again could feel it, and then at 80 and it was bad. It felt the same as going down the road. Removed the rear wheels and rotors and got the same vibrations at the same speed. Tried running it to about 90 mph and bumped it into netural and it had the vibration at 80, 40, and 20 mph as it was slowing down. I have come to the conclusion that it is one of the axle shafts but can't tell which one it is.

Any one have any ideas what else I could do. I can't take out one axle for several reasions.

Thanks for any help.

What happen when you drive this vehicle down the road at freway speed 70-80mph ? you will get vibration when the rear wheels is off the ground.

126
 

Well I have an 1985 500SEL That seems to do the same thing yours is doing except it is in the front end I think, my car vibrates so bad the star on the hood wiggles, hood vibrates. and again i have had tires balanced and rotated, new ones put on to see if out of round was a problem. rims seem to be not bent. I have done the new drive shaft, and new rear axles, Thinking this problem was in the rear..my car seems to be fine at speeds under 70 then at 75 it feels like its coming apart at the seems. I hope someone has a idea where to look..


Thanks

Rob..

Balance the wheels with a Hunter balancer I had the same problem, replaced the driveshaft and it still vibrated.

Had the wheels balanced with a hunter and it was gone.

John

Not just ANY Hunter balancer. You need to have them analyzed on a Hunter GSP9700.

You can go to: www.gsp9700.com and there is a locator icon that you can click on to find a shop near you that has one.

It applies pressure to the tire to determine if there are stiff spots in the tires.

Good luck,