Howdy all, i have a vibration thats been getting worse recently and it only occurs when i get on the gas or let off. I understand that this can be caused by a worn bearing/bushing for transfer case output shaft??? Can anyone shed some light? thanks.

could be a u joint

Block wheels, tranny in neutral and climb under truck. Grab the rear driveshaft and give it a good tug, top, bottom and middle (by the slip yoke). If you feel any side-side or up-down play, that may be the source of the vibes. If eitehr flange, could be a loose flange nut, remove shaft, unstake nut and torque to spec., restake nut and reinstall shaft.

I've been hearing/feeling something similar. At 60 or more, or when revving past 3K, a buzzy, metallic sound heard from trans/t-case area. Can be felt thru t-case shifter. Output bearing??

Again, you can usually feel if anything is loose. Get under the truck and grab hold of the t-case output and give it a tug. Usually should not be able to feel any play if it is tight. And for a 2nd test, pull the rear shaft and do a test drive in FWD and see if the vibes go away or not.

When my tcase went south, it started eating speedo drive gears. After the 2nd one was destroyed I dumped the oil because there were metal shavings embedded in the plastic gear (I guess I'm a slow learner because there were shavings in the first failed gear too). What came out of the case was chunky. When the case was pulled apart, it looked like a grenade had gone off in there.

It was the perfect excuse to pick up a rebuilt case from Jim at Inchworm with 4.7 gears in it. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Hopefully your tcase problems aren't that extensive.