Vintage Air Top Mount Squeal

[racecougar]

Further diagnosis this evening points squarely to the compressor pulley bearing. Adding tension via a ratchet to the tensioner makes it scream; relieving tension makes the squeal disappear. Soaping the belt makes zero change. Using the hose in the ear trick, the idler and tensioner pulley bearings are silent, but the compressor pulley is screaming (I think I'm still deaf in my left ear from testing earlier). The air gap between the compressor pulley and clutch plate is 0.025", which is within spec, and I see no sign of it rubbing. The gap is also even/square all the way around.

I'll forward this info to VA and Kwik and see where it goes now.