Topic: Throw out bearing or Input shaft bearing maybe?

[JeepManMarc]

When I am driving I can hear a bearing or somthing that sounds like a bearing, mostly at high RPM's just before shifting or if I let off the gass and let the jeep slow down, it isnt terribly loud, if you have the radio on even a little bit you cannot hear it.  I was thinking it might be a throwout bearing, but if the clutch is in, and you are moving, and you rev the motor, you can hear it at high rpm, I know for a fact it isnt in the engine, its in the tranny tomewhere.  I have concluded maybe the input shaft bearing in the transmission?  Im not even sure if I should worry about it, the Jeep only has 68k miles and it runs perfectly, just curious is all.
thanks for any insight provided,
-Marc

[Tall Boy]

I just r&rd mine. i could hear mine at idle for the 1st minute or so, then it goes away. Problem is the springs do not have enough tension to pull the realease bearing lever away from the pressure plate, so the bearing rides on the whole assembly. Mine usually last for 60,000 miles. I replaced the last one at 60,000, then that one broke at 103,000. My retainer clip that holds the bearing onto the lever broke.
 So, anywhere between 40 and 70,000 they can go bad. What sucks is the nuetral safety switch will not allow us to drive without the bearing,grinding gears. my clutch pedal was stuck, and would not budge.