97' 7.3L squeal

[BB77]

Hopefully someone here can help, I have had no luck at dealerships and throwing money (and parts) at this problem. I have had a squeal in a 97 F-350 4X4 that comes in under power and at about 1600 RPM and goes away when the truck shifts to the next gear. I am at a loss and am needing to get this thing ironed out. I have changed both idler pulleys, belt tensioner (2X), belt (4X), alternator (with pulley), water pump (2X), vacuum pump, vacuum pump pulley (2X), power steering pump, and cleaned the belts and pulleys MULTIPLE times. I am getting tired of throwing money at this thing. Hope something you know or have done can help me out.

I have not looked at other issues yet simply because it all seems to be happening around the belt area. It will sometimes squeal in park (or neutral) when the engine is brought up to 1600+ RPM

Thanks all!

[B4SouthernMiss22]

Is your air conditioner on when its doing this?

[BB77]

Sorry, forgot to mention that. It does not matter, does it with the AC on or off.

[B4SouthernMiss22]

I usually wouldnt recomend this but try some belt dressing and see if the squeel goes away.

[BB77]

Again sorry, tried that on belt #1... worked for a while then it came back. I keep going back to the belt but I have changed brands in this mix too and it has not helped. It did seem to go away when the vacuum pump pulley came apart and the belt shredded and all the accessories (and belt) stopped moving.

[BigFuel]

^Nice. Forgot to mention trying to stop the truck with no vacuum booster.

All the pulleys on the front end are lined up? Nothing crooked?

[BB77]

Yeah, that was interesting... (trying to forget that experience). Nothing looks drastically out of place, nothing appears to be out of round (pulleys). I am going to try cleaning the pulleys again with this new belt and see what happens this time. it has seemed to help temporarily in the past. I'm not sure about the belts being too soft and allowing rubber to buildup in the groves.
I really appreciate your help!

[BigFuel]

No worries, back in the day we used to just grab a bar of Ivory soap (standard plain white bar, for some reason that was the only one that worked) and hold it on the inside of the belt (grove side) and squeaks went away. So it doesn't do it just sitting there, you need to be on the power?

[BB77]

Yep! It is a bit annoying to pull away from a stop light and be squealing like a banshee...