Belts too tight?
Thread Starter
Pro
Joined: Oct 2020
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Belts too tight?
I've been chasing a squeal in my engine for a while now.
First I changed some belts that felt too loose, and that fixed it for a while.
Then it started up again so while it was in the shop they looked at it and said the PS pump was hitting the frame so they put a shorter belt in it to move the pump away from the frame.
It came back, worse after a few days.
I checked the belts and the alt belt was a little loose, so I tightened it up. The idler pulley was also a little loose so I tightened that too.
It's still there and I'm out of ideas. Could something be too tight at this point? I don't know where else to look...
Anyone nearby want to come check it out? I'll buy lunch!
First I changed some belts that felt too loose, and that fixed it for a while.
Then it started up again so while it was in the shop they looked at it and said the PS pump was hitting the frame so they put a shorter belt in it to move the pump away from the frame.
It came back, worse after a few days.
I checked the belts and the alt belt was a little loose, so I tightened it up. The idler pulley was also a little loose so I tightened that too.
It's still there and I'm out of ideas. Could something be too tight at this point? I don't know where else to look...
Anyone nearby want to come check it out? I'll buy lunch!
Le Mans Master
Joined: Jun 2019
Posts: 7,649
Likes: 2,466
From: Indiana
A harbor freight stethoscope and or heater hose to ear has been amazing for me..
my ps pump is almost hitting frame but that is because i put longer one on so i can actually remove and service my power steering fluid.. did you check fluid?
its so fascinating to hear the different components..the water pump is like smooth sounding,
the stethoscope is really clear but watch out for moving parts! Will it pick up squeal? Maybe ..it should transger noise vibration
my ps pump is almost hitting frame but that is because i put longer one on so i can actually remove and service my power steering fluid.. did you check fluid?
its so fascinating to hear the different components..the water pump is like smooth sounding,
the stethoscope is really clear but watch out for moving parts! Will it pick up squeal? Maybe ..it should transger noise vibration
Last edited by interpon; Apr 25, 2021 at 12:23 PM.
Race Director
Joined: Mar 2016
Posts: 14,321
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From: Napa Valley California
Make sure your belt driven components are adjusted and the bolts tightened properly.
Using a pry bar or screwdriver to get the proper tension on the belt and then tightening the bolts incorrectly could cause your pulleys to not be in alignment with each other and the belts may not be straight in the pulley groove.
Using a pry bar or screwdriver to get the proper tension on the belt and then tightening the bolts incorrectly could cause your pulleys to not be in alignment with each other and the belts may not be straight in the pulley groove.
Thread Starter
Pro
Joined: Oct 2020
Posts: 503
Likes: 139
All those sound like good ideas.
I guarantee that I'm not equipped with the knowledge to know if something isn't adjusted correctly or in alignment.
Spraying water on my engine I can probably handle...
Did not check fluid, would low fluid make squealing noise when engine is revved while sitting still?
I guarantee that I'm not equipped with the knowledge to know if something isn't adjusted correctly or in alignment.
Spraying water on my engine I can probably handle...
Did not check fluid, would low fluid make squealing noise when engine is revved while sitting still?
Safety Car
Joined: Sep 2005
Posts: 4,213
Likes: 643
From: Orange County Ca
Fan belts can be a lot more involved than most folks realize. Or not.
1 major problem I've encountered recently is the use of metric or thinner belts.
Belts should ride on their sides. If a thinner belt rides on the bottom of the pulley, you are getting a lot less friction. If your belts are riding below the rim of your pulleys, this could be the case. I believe that they should generally run mostly flush with the outside edge of the pulley.
A little off set of pulleys will freak some people out, but that is 1 of the good points of a fan belt. While desirable, it doesn't have to be 100% in line to work well.
Clean your pulleys. You may need to use sand paper if they're real rusty. Acetone will remove any oil or gunk. Acetone can also be used on the belts to remove oil and gunk.
When everything is correct, belts only need to be snug, not as tight as you can possibly make it which puts a lot of strain on bearings in the water pump, power steering pump, etc.
1 major problem I've encountered recently is the use of metric or thinner belts.
Belts should ride on their sides. If a thinner belt rides on the bottom of the pulley, you are getting a lot less friction. If your belts are riding below the rim of your pulleys, this could be the case. I believe that they should generally run mostly flush with the outside edge of the pulley.
A little off set of pulleys will freak some people out, but that is 1 of the good points of a fan belt. While desirable, it doesn't have to be 100% in line to work well.
Clean your pulleys. You may need to use sand paper if they're real rusty. Acetone will remove any oil or gunk. Acetone can also be used on the belts to remove oil and gunk.
When everything is correct, belts only need to be snug, not as tight as you can possibly make it which puts a lot of strain on bearings in the water pump, power steering pump, etc.
Last edited by Sayfoo; Apr 25, 2021 at 01:16 PM.
Melting Slicks
Joined: Dec 2009
Posts: 3,229
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From: Thunder Bay
A few years back I bought a replacement belt for one of my vehicles and the parts guy sold me one of those cogged belts. I couldn't get that thing to stop squealing until I replaced it with a conventional belt.
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Racer
Joined: Oct 2017
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From: Henry county ohio
Something else for you to check.
Inspect the pulley wear surface for polishing. It needs a certain amount of roughness. If it is really shiney, shinny, shi-nee, however the H it's spelled, the belt will slip.
Sand paper or bead blasting the pulley will usually bring the surface back to a useable surface. I prefer bead blasting.
Inspect the pulley grooves. They may be worn from a "V" shape, into a "U" shape, and the belt will slip.
If it's worn into a "U", the only real option is to replace the pulley.
And, yes, the belt is supposed to ride either flush, or just a bit proud. As long as it isn't riding deep in the groove, you should be good. If it is too deep.... the belt will slip...
Good luck.
Jeff
PS. Also make sure you have all the belts installed. Sometimes, the total drive load on the belts gets to be too much, if all the belts aren't contributing. And you guessed it... Slip
Inspect the pulley wear surface for polishing. It needs a certain amount of roughness. If it is really shiney, shinny, shi-nee, however the H it's spelled, the belt will slip.
Sand paper or bead blasting the pulley will usually bring the surface back to a useable surface. I prefer bead blasting.
Inspect the pulley grooves. They may be worn from a "V" shape, into a "U" shape, and the belt will slip.
If it's worn into a "U", the only real option is to replace the pulley.
And, yes, the belt is supposed to ride either flush, or just a bit proud. As long as it isn't riding deep in the groove, you should be good. If it is too deep.... the belt will slip...
Good luck.
Jeff
PS. Also make sure you have all the belts installed. Sometimes, the total drive load on the belts gets to be too much, if all the belts aren't contributing. And you guessed it... Slip
Last edited by jeffwebley; Apr 25, 2021 at 02:19 PM. Reason: Additional info
Le Mans Master
Joined: Aug 2017
Posts: 8,336
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From: Cool Northern Michigan
Sayfoo ^^^^^^^ is correct. Ever since the cardboard sleeves on new belts went metric, the width seems to be narrower. This is from the NAPA parts counter guy.
This also makes the belt a pinch longer because it no longer rides as high in the pulley.
We are mad as hell and we are not going to take it anymore! Bring back the American measurement of inches.
This also makes the belt a pinch longer because it no longer rides as high in the pulley.
We are mad as hell and we are not going to take it anymore! Bring back the American measurement of inches.
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THey do make them in inches, its part of the part number and the wider belts are the first 2 digits so a 15230 is a narrow belt with the 23.0" inch circumference. 17230 is a wider belt that is 23.0" a 17235 is 23.5" so you can go up in down in size by the half inch
I just got this education from a parts store guy...behind the counter...really, he actually knows what he is talking about. THere is actually a good handful of guys local to me that really now about the old small stuff
I just got this education from a parts store guy...behind the counter...really, he actually knows what he is talking about. THere is actually a good handful of guys local to me that really now about the old small stuff
Last edited by Rescue Rogers; Apr 26, 2021 at 09:04 AM.
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If your belts squeal shortly after installation and appear to be too loose and you are positive you tightened the adjusters properly, this is a sure sign of pulley misalignment. Misaligned pulleys will stretch your belts prematurely.
The easiest way to check this is with a straight edge laid across the face of a pulley so it avoids the pulley crown and touches the outer edge of the sheave in two places. While maintaining contact, rotate the straight edge and see where it contacts other pulleys. You may need to remove the fan belts and even the fan to do this, but it is worth it or you will never resolve the problem. Also, pay close attention to the thickness of the sheave edges. Your pulley may appear to be perfectly aligned using the straight edge, but if one has a 1/8” face and the other a 3/16” face they can be misaligned. In the ideal world if you have misalignment, the crank and WP pulleys are aligned and the misaligned pulley(s) are closer to the engine. It is much easier to shim them out into alignment than to figure out how to move them back successfully. Good luck!
The easiest way to check this is with a straight edge laid across the face of a pulley so it avoids the pulley crown and touches the outer edge of the sheave in two places. While maintaining contact, rotate the straight edge and see where it contacts other pulleys. You may need to remove the fan belts and even the fan to do this, but it is worth it or you will never resolve the problem. Also, pay close attention to the thickness of the sheave edges. Your pulley may appear to be perfectly aligned using the straight edge, but if one has a 1/8” face and the other a 3/16” face they can be misaligned. In the ideal world if you have misalignment, the crank and WP pulleys are aligned and the misaligned pulley(s) are closer to the engine. It is much easier to shim them out into alignment than to figure out how to move them back successfully. Good luck!
Thread Starter
Pro
Joined: Oct 2020
Posts: 503
Likes: 139
If your belts squeal shortly after installation and appear to be too loose and you are positive you tightened the adjusters properly, this is a sure sign of pulley misalignment. Misaligned pulleys will stretch your belts prematurely.
The easiest way to check this is with a straight edge laid across the face of a pulley so it avoids the pulley crown and touches the outer edge of the sheave in two places. While maintaining contact, rotate the straight edge and see where it contacts other pulleys. You may need to remove the fan belts and even the fan to do this, but it is worth it or you will never resolve the problem. Also, pay close attention to the thickness of the sheave edges. Your pulley may appear to be perfectly aligned using the straight edge, but if one has a 1/8” face and the other a 3/16” face they can be misaligned. In the ideal world if you have misalignment, the crank and WP pulleys are aligned and the misaligned pulley(s) are closer to the engine. It is much easier to shim them out into alignment than to figure out how to move them back successfully. Good luck!
The easiest way to check this is with a straight edge laid across the face of a pulley so it avoids the pulley crown and touches the outer edge of the sheave in two places. While maintaining contact, rotate the straight edge and see where it contacts other pulleys. You may need to remove the fan belts and even the fan to do this, but it is worth it or you will never resolve the problem. Also, pay close attention to the thickness of the sheave edges. Your pulley may appear to be perfectly aligned using the straight edge, but if one has a 1/8” face and the other a 3/16” face they can be misaligned. In the ideal world if you have misalignment, the crank and WP pulleys are aligned and the misaligned pulley(s) are closer to the engine. It is much easier to shim them out into alignment than to figure out how to move them back successfully. Good luck!
Team Owner
Joined: Jan 2006
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From: Crossville TN
There are belts which have different "V" shapes. You need to select the belt design which fits properly to your vehicle. Also, you must have belts wide enough so that the inner surface DOES NOT touch the bottom of the groove. If it does, the belt will slip and squeal.
Ideally, the outer surface of a properly sized belt will run at the same level as the outer diameter of the pulley[s] on which it is running. Plus or minus of that is OK, as long as the 'sides' of the belt are [nearly] fully engages with the sides of the pulley grooves and the inner surface is not in contact.
Ideally, the outer surface of a properly sized belt will run at the same level as the outer diameter of the pulley[s] on which it is running. Plus or minus of that is OK, as long as the 'sides' of the belt are [nearly] fully engages with the sides of the pulley grooves and the inner surface is not in contact.
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Melting Slicks
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From: Dunedin NZ.
Hi, some history would be helpful, I see you joined the forum fairly recently, what year is your car and how long have you had it? Have any changes been made and then the squeal appeared? When I first got my car it had a belt squeal problem when starting and nothing I tried fixed it for long, it turned out that the belt setup was incorrect leaving one belt from the crankshaft pulley carrying all of the load - water pump, PS pump and alternator. Once this was sorted no more squeal.
Thread Starter
Pro
Joined: Oct 2020
Posts: 503
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Hi, some history would be helpful, I see you joined the forum fairly recently, what year is your car and how long have you had it? Have any changes been made and then the squeal appeared? When I first got my car it had a belt squeal problem when starting and nothing I tried fixed it for long, it turned out that the belt setup was incorrect leaving one belt from the crankshaft pulley carrying all of the load - water pump, PS pump and alternator. Once this was sorted no more squeal.
See lots of info here https://www.corvetteforum.com/forums...out-belts.html
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