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Horrid screeching after new belts

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justin0469

20+ Year Contributor
1,004
10
Apr 4, 2003
san diego, California
So its my first belt job, because the old belts were cracking and falling apart. I install new PS and alternator belts but only to hear even worse screeching then ever before! I dont see how I messed it up but what did i do wrong and how do i fix it?
 
Hey i had the same problem when i did my belts. I forgot to retighten the bottom bolt that runs through the alternator. Pretty simple fix. If your smarter than me and didnt forget how much play is there in the belts? Is water able to splash up in there?
 
I actually tightened it pretty good but my room mate suggested that i tightened too much so i loosened it a little and it seems fine but im goin for a drive so we will see
 
So i loosened it and all was well for a few miles and then it went to hell for like 1 min or so then shut up. now it happens every so often. I know its the alternator belt though. maybe its too loose now?
 
Yuup re-tighten it a bit more. This happened to a buddy of mine, we re-tightened it and it was al good.
 
well im hoping that since this was not an issue previously that its a problem with tightness
 
Continual belt squealing problems sometimes aren't from the belts. Put a mark across the rubber part of the pulley. Check later to see if part of it has shifted.
 
I started a thread a week or so ago on this. I changed my underdrive pully to a stock one and also found that my tensioner bolt had vanished. Both fixed and no problems since. Hope this helps.:talon:
 
like i said, its my first belt job and im still learning things, but which pulley is the underdrive pulley and what tension bolt are you talking about? i know about the adjusting bolt for the alternator belt....
 
An underdrive pulley is an aftermarket performance pulley. He is refering to his crank pully or harmonic balancer as others call it. Is what happens is the pulley will break into an inner and outer ring. The bolt i was refering to is the bolt that runs through bottom of your alternator that essentially locks in the tension you create with the tensioner bolt. Its kind of difficult to get to making it an easy one to forget. Im not sure if this is the same bolt that 92fasttalon is reffering too or not. Hope this helps a bit.
 
I wonder if there is a certain rotation side the belt should be installed since the tension seems to be up to spec.. just a thought
 
no belts can go any way tighten the belt and with to fingers move the belt up and down make sure the belt is not to tight or to lose
 
wret said:
Continual belt squealing problems sometimes aren't from the belts. Put a mark across the rubber part of the pulley. Check later to see if part of it has shifted.

Are you sure the marking would line up on each rotation? Are the stock pullies at a even rotation rate (1:1 2:1 etc) or are they something in between (1.25:1 etc)?


justin0469 said:
I actually tightened it pretty good but my room mate suggested that i tightened too much so i loosened it a little and it seems fine but im goin for a drive so we will see

You can check what the belt deflection should be in a manual. I would assume it should be a little over 1", but make sure you check.
 
Dan7040 said:
Are you sure the marking would line up on each rotation? Are the stock pullies at a even rotation rate (1:1 2:1 etc) or are they something in between (1.25:1 etc)?

You are making it too complicated. Make a line across the rubber section of the balancer pulley. Run the motor. It might be a good idea to start it cold, rev it a little and let it warm up. Turn off the motor. Check to see if the line on the pulley has shifted.
 

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so you may want to slap me for asking this but i just want to make sure, the balance pulley is easiest described as the pulley that is not attached to some external part like power steering pump or alternator right?

And right now the car isnt running so I cant test this just yet, hopefully in a couple days but what happens if its not lined up?
 
justin0469 said:
so you may want to slap me for asking this but i just want to make sure, the balance pulley is easiest described as the pulley that is not attached to some external part like power steering pump or alternator right?

And right now the car isnt running so I cant test this just yet, hopefully in a couple days but what happens if its not lined up?

It is the pulley that attaches to the crank, down by your oil pan.
 
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