vibration in my 740il

[cool740il]

Help. I have a 2000 740il. It has a vibration that I am having trouble tracking down. This vibration occurs around 65 mph. It happens under load or just coasting. It's a vibration that seems to oscillate or should I say come in and out at a steady beat. New tires with road forced balanced, new brakes "rotors, pads" and alignment. It has 121K miles. But here's the funny thing. Sometimes it doesn't happen at all.

One thing I haven’t done is replace the wheels.

Any help would be appreciated.

Thanks.

[shogun]

do a search on this E38 board, I just typed in vibration and something like this example came out
http://www.bimmerboard.com/forums/posts/505514/

[mt manager]

The wheels can be checked on a wheel balance machine for run out and warp, if they were bad I would think your tire fitter would have alerted you to this. I would check the Prop shaft couplings, bearing and mounting for wear. the fact you can affect it by applying power, indicates to me the drve coupling at the front of the diff is deteriorated. At the mileage you have they could be due for a change. Also the oscillation frequency of the shaft is much faster than roadwheel frequency as it rotates almost 4 times faster.