Pulley/Belt Noise

[Comp112]

Hey yall, so I got my 96 5.7 Suburban running, and dialed in pretty decently.

My current issue is a squeak from either a pulley, or AC/PS pump.

I already removed the belt and ran it, no noise. I checked all the pulleys for play/noise, including the tensioner, and that checks out. The PS pulley is even as well.

Now, I did end up having to shim the AC up to clear the new valve covers. This I assume would increase distance, and with the same belt cause it to tension tighter. The serpentine belt looks to need replaced either way, but would it be a good idea to grab the longer belt instead?

 

[AuroraGirl]

Hey yall, so I got my 96 5.7 Suburban running, and dialed in pretty decently.

My current issue is a squeak from either a pulley, or AC/PS pump.

I already removed the belt and ran it, no noise. I checked all the pulleys for play/noise, including the tensioner, and that checks out. The PS pulley is even as well.

Now, I did end up having to shim the AC up to clear the new valve covers. This I assume would increase distance, and with the same belt cause it to tension tighter. The serpentine belt looks to need replaced either way, but would it be a good idea to grab the longer belt instead?

does your tensioner have a dial indication on it to show where the tensioner is in swing?

 

[Comp112]

does your tensioner have a dial indication on it to show where the tensioner is in swing?

Off the top of my head I am not sure. If it does, does it need to be pointing in a specific area?

I should note that the noise is lessened, to totally gone as I crank the steering wheel.

 

[someotherguy]

Belt may be slipping a tiny bit due to contamination. If it got oil on it, or even coolant, it can be difficult to get it clean and quiet again. I once fought a belt for this on a water pump job. The pump had gone bad with the bearing in it making noise. Replaced with new, and the new pump made noise, too? It turned out to be bad out of the box. Got a pump from a different source and it was quiet, but the belt was now squealing. I was ready to blow the truck up. Turned out some coolant that spilled on the belt caused it. Was also compounded by some soft paint on the water pump pulley that the belt started riding on because one of the pumps hub was offset just a tiny bit so the belt rode past the worn area. Belt was pretty new so I took a stab at spraying the grooves of it and the pulleys out with some Brakleen and it was quiet again. The chemical may have shortened the life of the belt a little but not as much as all the aggravation shortened mine..

Richard

 

[AuroraGirl]

Off the top of my head I am not sure. If it does, does it need to be pointing in a specific area?

I should note that the noise is lessened, to totally gone as I crank the steering wheel.

The body of the tensioner that stays still should have 2 or more marks and the part that moves should have a mark and that mark should stay between the outer limits of the other 2

 

[Schurkey]

...and the tensioner should be steady, not wiggling back and forth. If the tensioner wiggles, either something is bent, or the damper inside the tensioner is worn-out. Worn-out tensioner is more likely than bent parts.

 

[Comp112]

Alright, so before I hit the parts store this morning I did some extra checking. Tensioner and pulleys, all with no weird movement, no noise.

Went and grabbed a same size belt, better but wasn't right. Swapped it for the 96.7 inch belt, and its mint now. The way they wrap the belt for packaging is annoying, only due to it making it more annoying to put the belt on.

Now that the noise is gone, I can really hear the alternator complaining again. But that is a pretty easy fix there.

Thank you all again for the advice!

 

[AuroraGirl]

...and the tensioner should be steady, not wiggling back and forth. If the tensioner wiggles, either something is bent, or the damper inside the tensioner is worn-out. Worn-out tensioner is more likely than bent parts.

In a V8 this is for sure , the tensioner should at most have small corrections that arent sharp, in a v6 there is to be more. the tensioner spring like you said is more likely to be worn if the thing is like a metronome. @op, the marks if you see them should be more or less in the center area between the extreme outer marks, because that is the indicator of the belt being the right length and having the room for wear + tolerances in the travel.

also, if the sound goes away under steering, if you can easily access your steering pump, I would pull the flow control valve out and see if there is scoring on the walls of the pump and wear on the valve that could be causing it to stick in its bore or have issues using its bypass. not saying it still cant be other parts. does your truck have a power steering switch(Idle boost to prevent the engine from stall or lugging under load)