w210 4matic drive train vibration question!
 

I have a 2001 e320 4matic wagon that has started to develop a high frequency vibration when the car is running around 40 MPH and I let off the gas. The vibration is a higher frequency then you would experience from an out of balanced tire. The tires are about 70% worn. Is it possible that asymmetrical tire diameter is causing the vibration?

Start by swapping tires around. If there isn't any difference, then a front axle is the most likely issue.

Thanks, I'll give that a try.

Update: moving the front tire to the rear and rear to front stopped the vibration. Looks like it's time for new tires. Thanks for the help.

Maybe a bit late, but I have a recommendation as well.

Noise and vibration may come from wrong tyre wear (as we call it - the tyre gets worn in the shape of a sprocket-wheel and that makes the noise). Tyre wear on the 4M front axle may be impacted by worn rubber parts on the transverse control arm. Im talking about nr.59 in the picture.
http://ci.catcar.info/mercedes/BM/B3...009.970129.jpg

So, swapping back to front would solve the problem for a while only until the wrong wear sets in.
I've had a 4M W210 for more than 3 years and I have a set of winter tyres that were silent at first but now they make the car sound like a dive bomber of WW2.
The worst that could happen in this respect is that the car develops notable vibration at acceleration. Most likely due to the wear of the rubber unit under the front shock absorber. Because after replacing the repair kit nr.59 all vibration was gone. I assume that also the wrong tyre wear pattern is not likely to happen either.