hey all, i was lurking around in this forum for while and unfortunately this is my first post since i have some vibration problem on high speed..
i thought it was my tires, or wheel balancing, but changed 4 new tires and fresh balance, the 50mph-70mph vibration is still there.. i tried putting the gear on neutral when i was going 60mph, the car still vibrates, so its not the engine i guess,..what could be wrong? wheel bearing? is this a common problem?
my car is 2004 e500 4matc

 

Could be a damaged wheel.

 

Good call Barry.
Balancing (even with "Road Force" balancing machine) won't correct for a bent rim.

 

i had the same, turned out a wheel was bent. Upgraded to 18" and now it is as smooth as butter

 

Also Some aftermarket rims are of poor quality

Seen even NEW tires out of round

Any decent Hi Line tire shop should be able to help you find the problem

 

Definetly bent rims. A small disruption in the circumference of the rim will cause an annoying vibration at speed.

 

thank you so much all!!. i guess i hit a pot hole and the tire shop i went didnt tell me anything if it is bent or not. they probably knew when they were doing the balancing..
well i guess its time for upgrade to 18's
thanks!

 

I've had a similar experience on my 500 4matic - in my case it turned out to be a left upper control arm - it was replaced under warranty - I'd definitely have it checked out - in addition have you had the transfer case recall done to yours? Be sure your car has had all the factory called for updates and service bulletins - the dealer should have a record of all required service and updates -

 

I was having similar problem on my '06 E500. New transfer case and road force balance made the problem go away. The transfer case was a recall item.