help ID strange sound after revving

[1968SWTs]

I was asked to ID this sound but I am stumped
really strange - after some clutch slip on a steep incline a "spinning" noise independent of engine speed after a rev - almost like a Model T Ford Aaoogha horn spinning after the engine slows

clutch hub?
fan clutch
alternator clutch
power steering
a/c compressor
.. ?

[Bob Kontak]

Where was the recorder positioned when the sound clip was made?

I think you need two people and one to listen while laying on the ground in front of a rear wheel to see if the noise is coming from the transmission (clutch) area.

It almost sounds like tired bearings making noise after load is taken off of them. I have never heard a clutch noise like this but I am not a hard core lifer mechanic.

[flat6s]

If the engine is running at the beginning of the clip, then why isn't the fan spinning ?

[pete3799]

Originally Posted by flat6s

If the engine is running at the beginning of the clip, then why isn't the fan spinning ?

I'm baffled too.

[Ayles]

Probably just a static image uploaded with the sounds from the recorder on an iPhone. There is zero movement in that video.

[pors1968]

Hard to say but i would go for vacumm line .