I have a 2005 ml350 and there is a noise in the drive line that I cant find. I have changed the center bearing but that wasn't it. the noise is louder when cold and sometimes cant hardly be heard. thanks for your help

thanks for your input. I don't know what the flex disc is but my noise is more of a whining noise that changes a lot. its different if iam on the gas and it might sound might be different when iamm on the gas the next time. I thing it my have something to do with someone not running the same size tires.