190E shaking

[benzguy300]

I have a 2.6 190E that shakes when I’m doing 55 mph it doesn’t shake when I’m going faster or slower I thought someone here in this forum had this problem and might point me where to look

[Mxfrank]

Have you lost a balancing weight on a tire or dented a rim? If so, it would vibrate when the rotation speed was at the resonant frequency. Above or below, you wouldn't get much shake. Try rotating your tires and see if it changes.

[benzguy300]

No I haven not lost a balancing weight or dented a rim but I swapped tires and I think they aren’t balanced thanks for the reply

[Ferdman]

benzguy300, best to have wheel balancing done on a Hunter Road Force Balancer. Be prepared to spend $20 to $30 per wheel … so you want to have new/newer tires to justify the cost.

[Duke2.6]

Most likely the steering damper has failed. This first time this happened to my '88 190E 2.6 about 20 years ago the front end went into a shimmy the likes of which I have never experienced before. I was just as you say... centered about 55 MPH, but not evident at all below 50 or above 60. It happened again a few years ago, so I immediately recognized the problem.

It's easy to test. Assuming your engine underpan is still there, remove it. If there is evidence that the damper is leaking oil (not just a slight film), it's likely failed. Remove one end and move it back and forth. If there is little resistance it's failed.

Like the suspension dampers the steering damper is a DeCarbon type damper, like high pressure suspension dampers pioneered by Bilstein. Rather that deteriorate slowly like typical hydraulic dampers, they generally maintain their original damping characteristics, and then suddenly and completely fail, usually evidenced by loss of the oil. The failure allows the high pressure gas to escape and then the oil follows.

Some years ago I found a puddle of oil under the RF suspension just inboard of the tire and further investigation indicated that the strut has lost all damping. Unlike typical hydraulic shocks, which should usually be replaced in pairs, it's okay to replace high pressure gas dampers singly. All the other suspension dampers on my car are original.

IIRC the last steering damper I bought from Pelican was about 25 bucks, and it's very easy an quick to change with normal hand tools.

Duke

[benzguy300]

Mxfrank hit the nail on the head thank you. I went to a tire shop and one of the front wheels lost a balancing weight they balanced the two front wheels and the shaking is gone. Thank you guys