Whining noise, any guesses?

[TexasTruck72]

Today, while driving my 72 F-100, I heard a whining noise come and go every time I'd reach 45-50 mph. It usually didn't hast but a few seconds and then fade away. And it was not sounding off all the time. It was a very high pitched whine that was almost bad enough to be painful to my ears. I realized it had something to do with the transmission/clutch for when I'd press the clutch pedal down, the noise would die down and trail off quickly. My truck has a 3 speed transmission, column shift, and 360 V8 all original to the truck. Any ideas what I might be hearing? Do you think this is even related to the transmission or clutch?

Any help much appreciated. Thanks.

[papabug71]

Throw out bearings have been know to make some weird sounds. My truck would wine if I pushed the clutch all the way to the floor.

Listen to my video in the link. At :39 you can briefly hear the noise my throwout bearing makes if I clutch to the floor. Does it sound anything like that?

http://www.youtube.com/watch?v=IFMJ4uDJ ... A&index=10

[TexasTruck72]

Thanks papabug71. Possibly the same sound/cause. Still hard to tell at the moment. I'll keep listening for it and try to pin point it better. I'll keep you all updated if I find out something else. Thanks!