djmacc

My wife has a 1998 #320 4matic with about 80,000 miles and it has a vibration I am trying to track down. It starts around 55 is worst around 63 and get better at higher speeds. The vibration is not in the steering wheel but rather you tend to feel it thru the seat and the floor. I am not familiar with the flex disk in the mercedes but to me what she has a similar vibration as a bad u joint but of course I do not have the tell tale clunk when shifting from reverse to drive you get with a u joint. Is there a way to check for a bad flex joint? I took a look underneath and between the tranny mount and everything else I cannot even get a hand the flex disk.

sosh

Have you had the rear tires balanced?? I would look there first. It could also be a bad rear tire with a bad belt.

ETP

I would look to the tires first as well. Rotate them and check balance. I know it sounds simple but I have had great sucess checking the simple and CHEAP stuff first. Good luck post your results when you get it sorted out..

djmacc

It is about due for a set of tires so I will start there and let you know.

Britrover

Like others have advised check the tires first. If that does not fix the issue have your mechanic list the car and inspect for leaks in the rear.

My car was vibrating and making agrinding noise and it was a seal in the rear differential.

Hope this helps. Best of Luck.

fdte320

Could be the rims are out of round or wobbly. The tire technician will be able to tell you if the rims are out of round or wobbling at the balance machine.

ccmbduong

Could it be engine mounts?

HOWSER

Here's another vote for tires. If they are nearing replacement I bet money that this is the issue.

rmeneses

My tires aren't even a year old and it vibrates, new bushings, tie-rod ends, tire balance etc...

sosh

Just because thee tires are not old does not mean that they can't be out of balance or they can't be defective with a bad belt. I would go from these points first. Has the other stuff you mentioned been done or is it that you are asking that it should be done?? That stuff could cause the problem but its quite easy to have it inspected by someone who knows what they are doing to determine if in fact it needs that work.

fosmith

I agree it's most likely tires but could worn wheel bearings also cause this?

jaak

Does it change under load? or go away? Does it do it while coasting? Does the sound change while turning one way or the other and coasting? (Find an empty parking lot)

It could be tires, wheel bearings, CV joints, diff bearings, and depending on what/when, you may be able to narrow it down. Wheel bearing and tire noise don't go away change significantly when you lightly change the loading on the drivetrain, in my experience. However something like a bad pinion bearing, will...