Belt Squeal after alt swap on Y-block

I've gotten 500 different anwers for this so i'm hoping you guys can help. Used the Alternator conversion kit from Concours parts, and it squeals really bad now. It's just a 1-wire GM alternator. Does it sound right that they pulley could be too deep for it? We had to roll the belt onto the pulley so I don't think a shorter belt could be put on, and it's all lined up right. Do ya'll think a shallower pulley could help solve it? Really appreciate input.


Pic of pulley for reference

 

looks like the v belt is bottoming out in the alternator pulley. the belt needs to wedge it self in to pulley without bottoming out to grip enough

 

wrong or worn belt or pulley

 

Used a laser to check them.


Forgot to say you can spin the alt pulley when the belt is on it, has some resistance to it though.

 

i really like the idea of using a laser to check pulley and belt alignment. especially while engine is running.

 

Looks like you need a narrower pulley or a wider belt. How much of the pulley does the belt contact? It needs to contact at least on third of the surface of the pulley. A cogged belt can help get more grip.

 

If you can turn the alternator fan by hand, the belt is too loose or not getting a grip on the pulley.

 

Look at your crank pulley as well. You should see "shiny" on the sides of the "V" and no shiny on the bottom. Check the water pump & any idlers as well. If you are satisfied with the contact area and location on the crank/water pump/idler pulleys, change the alternator pulley to match the "V" of the others. If all your pulleys have evidence of contact on the bottom, go to a wider "V" on the belt. Your pic was worth a 1000 words, as they say.

 

compare the width of that alternator pulley to the other pulleys on the motor. Looks like you have a wide groove pulley and you are using a narrow belt. The belt will slip if it bottoms out in the groove like that one is.

 

Fold the belt in half and lay it in the pulley so you can see underneath the belt to get an accurate idea of pulley to belt contact.

 

Measure your pulley and compare to this one;



Or pick from here;

http://store.alternatorparts.com/pulley.aspx

http://www.gates.com/catalogs/BELT I.D. CHART 2012 SM1.pdf

 

Water pump pulley


Alt with the belt on it


Water pump with belt


Would say the alt pulley is too wide yeah? Thanks for the help so far guys.

 

Swap out the pulley. You can see it's too wide in the photo.

 

That alternator pulley is NFG, it is to wide. You need to get one that is the same or near to the same width as the water pump pulley.

 

As per posts 14 & 15. Pulley is too wide. Other reasons sometimes can be belt tension incorrect, and I've even heard them squeal just because the belt is new.

 

Little update, got the new pulley put on and it no longer squeels. Thanks a ton guys.

 

Show a picture of the original Y-Block pulleys. It appears to me that your belt is too wide for the late model pulley. The burnt rubber is too high in the grove.

McGurk

 

The belt is bottomed out because the pulley is too wide. The shiny part is where the belt is slipping.


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