Large Vibrations at mid rpm range

[larz18]

Just wanted to see if anyone had any ideas on this one. So i get a high pitched vibration under deceleration only right around 1800-2000 rpm range. This is the only range it will vibrate and only at freeway speeds. Any ideas. It feels like its right under my feet and will vibrate only at that range, once it drops below 1800 the vibration stops imediately and if your in that range of vibration and you push on the gas it will also go away. Wierd.
Thoughts
Thanks

[greyghost07]

I know this was 2.5 years ago, but I have the same exact problem with my 07 8" lift, what did you ever find out???

Thanks, Kevin

[steeldiesel]

My 2001 is having the same growl. Only while decelerating. Touch the trottle slightly and the noise is gone. 4r100 transmission????

[Nick]

I would like to know if your truck has a manual tranny? If you did I would say that it was the problem because I have an OBS and I have the same vibration, and it was the dual mass flywheel that was coming a part.

[greyghost07]

Automatic, 5100R just rebuilt with HD converter, had it checked by two different tranny shops because I thought it was a botched rebuild...wasn't. Tranny is just fine...

[steeldiesel]

If you were experiencing the vibe; then what was your problem greyghost?