P/S belt squeal

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Ricks70Duster340

Child of the King
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Have been chasing a squeal for some time now and narrowed it to the P/S belt. The belt was very tight so that was not the issue. Was using a Dayco 15465 so thought I'd try a Gates so got a XL 7465. It squeals more than the Dayco one did. I tried gently sanding the pulleys which made no difference. The belt rides just a bit high on the P/S pump and is below level on both the water pump and crank pulleys. I don't know where these pulleys came from and are likely not original.

Any thoughts on how to stop the screaming??
 
The fact that the PS is on the water pump pully tells me it not a factory setup. PS belt should be fron crank to PS only. Is the alternator belt on the water pump also? Picture?

Are the pullies square with each other and lined up front to back? Nothing cocked sideways? Is there paint in the grooves? Do you have any oil on them? Clean the pullies with brake clean.
 
I have had the ps belt squeal that has driven me nuts. I have done two thing that have helped:

1. Aligned pulleys. Mine were off quite a bit.

2. Bought a belt without cogs. Dayco top cog I think.

Those two things have helped a lot.

I think it is the water pump pulley that squeals.
 
Pictures...

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The fact that the PS is on the water pump pully tells me it not a factory setup. PS belt should be fron crank to PS only. Is the alternator belt on the water pump also? Picture?

Are the pullies square with each other and lined up front to back? Nothing cocked sideways? Is there paint in the grooves? Do you have any oil on them? Clean the pullies with brake clean.
Alternator belt is on the crank to the A/C compressor. Edit: everything looks lined up well. I used brakeclean this morning on the pulleys and it made no difference.
 
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My theory is that the belt drives were designed with non cogged belts. Cogged belts have ~1/2 the surface area to grip. Don’t know whether that is true or not, but seemed to help me.

I bought a fractional horsepower belt from Grainger and squeal went away completely. However, they are not designed for auto use and only last about a year with light driving.
 
The pulleys you have are either pre-'69 or for a heavy truck application with a wider groove and the larger PS pulley od. The good news is it looks like they all match for the PS groove. Try a 9 instead of a 7 first digit for gates (9465) or 17 instead of 15 for the other numbering system for a 1/2 inch wide top. and grab a couple longer belts to find the best length, then return what you don't need. The wider belt will require adjusting the PS pump inboard for the same length circumference so it may require a longer spec.

Cogged are made for smaller diameter pulleys like alternators.
 
Cogged belts are made in several widths. The idea is it has all the edges of the cogs to grip the pulley. I think they work better. I don't like the cogs on outside, they look odd and don't help anything.
 
Get a non-cogged belt. The cogged belts stretch more simple because there is less rubber taking the load. Cogged belts were invented to reduce flexing & heat build up so that the belts lasted longer. Downside is more slippage.
 
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