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Chirp after Replacing Harmonic Balancer!

Old 09-14-2006, 10:18 PM
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Jharms
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Default Chirp after Replacing Harmonic Balancer!

Help!

A couple of weeks ago, I took the plunge and replaced my own harmonic balancer. It had seperated and the belt was starting to come off. It was a big job, but with the help and illustrations offered by this forum I was able to do the work.

I'm highly confident that I did the job "by the book" with the following exceptions.
  • I didn't have a long bolt to start the new harmonic balancer so I got it started by tapping with a hammer.
  • I didn't have a tool to keep the harmonic balancer from turning the motor so I stopped it by wedging a screwdriver in between the harmonic balancer and the motor.
  • When going through the torque process, I tighten to 240 ft lbs with the old bolt, removed the old bolt, tightened the new bolt to 37 ft lbs. However, when I tried turning the certain number of degrees, the motor turned. So I tightened to a little more than 200 lbs.

Now everything works, but it has a chirp. At first, I thought it might be the belts just seating in. It seems to be worse when cold and better when hot.

I can spray WD-40 behind the new harmonic balancer and it makes the chirp go away, for a short while.

Any ideas? Does anyone know approximately what the torque would be when properly turned the correct number of degrees after being torqued to 37 ft lbs?

Help! This noise is killing me. People are staring.
Old 09-15-2006, 01:17 AM
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mfrejek
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I'm confused about using the wd40, all that's behind the balancer is a crankshaft seal. Remove the belt and start the car, it will run. If the noise goes away, it's the belt. My guess is you're belt is shot, or has something on it.
Old 09-15-2006, 07:36 AM
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zo6vetteman2003
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Originally Posted by Jharms
Any ideas? Does anyone know approximately what the torque would be when properly turned the correct number of degrees after being torqued to 37 ft lbs?

Help! This noise is killing me. People are staring.
Yes, 37ft/lbs. is correct and then another 140 degrees.
Old 09-15-2006, 07:51 AM
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vettenuts
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The turning after torque does not equate to a torque, people may give you a number, but it is a pre-defined preload/stretch on the bolt defined by the thread pitch. Torque can vary a great deal due to thread friction, so the pre-defined turns provide better definition of stretch. This is why ARP wants you to use their lube on their bolts, they then know the friction coefficient. I think when you posted your method I had stated you might have issues. There is a rubber compound that separates the inner hub from the outer. This rubber is there to damp out the crankshaft harmonics. The chirp to me is an indication that there is now an issue with the balancer and I personally would swap it out using better methods/tools. Here is the tool I made to install mine, simple and cheap.

Old 09-15-2006, 08:57 AM
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Originally Posted by vettenuts
The turning after torque does not equate to a torque, people may give you a number, but it is a pre-defined preload/stretch on the bolt defined by the thread pitch. Torque can vary a great deal due to thread friction, so the pre-defined turns provide better definition of stretch. This is why ARP wants you to use their lube on their bolts, they then know the friction coefficient. I think when you posted your method I had stated you might have issues. There is a rubber compound that separates the inner hub from the outer. This rubber is there to damp out the crankshaft harmonics. The chirp to me is an indication that there is now an issue with the balancer and I personally would swap it out using better methods/tools. Here is the tool I made to install mine, simple and cheap.

Nice post vettenuts. The chirp initially I was thinking was coming from the belt, because the balancer is not in alignment with the other pulleys. If the balancer bolt comes loose, it will back the balancer off for sure. Yes, 140 degrees is from GM. I assume this to be the torque angle, although it wasn't stated that way in my book. This extra 140 degrees takes two men and a small boy to achieve btw. The original bolt is a one time user as we both know. He may have stretched the new one, and it has backed off, is what I was thinking, unless it is an ARP bolt. The ARP takes the worry away without being concerned with the torque to yield. The ARP lube does provide a more accurate torque reading as you stated regarding friction. To keep the balancer from turning, I put the car in 4th gear and proceeded to crank.
Old 09-15-2006, 10:03 PM
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Jharms
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Good suggestion about taking off the belt and seeing if it chirps. I used a bar of soap on the turning belt with no change in sound. I thought that may make a sound difference if it was the belt.

I've got an automatic, so I can't use the 4th gear trick to keep it from moving. Good suggestion though.

After the 37 degrees, I turned it the same as two men and a boy. My torque wrench was set to 200 ft lbs and it clicked and then I went a little more. I really don't think that its too loose. I'm wondering if it's too tight!

This weekend I'll take the belts off and see what she sounds like. After that, does anyone else have any suggestions?
Old 09-15-2006, 11:49 PM
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Jeff Jeff
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It does not sound like you used the proper method to seat the pulley -- using the crank threads to pull it on. Plus the "wedge a screwdriver" thing worries me.

My guess is that you did not install the pulley correctly and it is not properly aligned. I would venture to guess that in a few days or weeks, you will shred your a/c belt, then your main belt, and if you don't catch it in time, your pulley will back all the way out. If it does come all the way out, expect some serious damage.

How many miles do you have on it since the swap?
Old 09-16-2006, 12:07 AM
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Originally Posted by Jeff Jeff
It does not sound like you used the proper method to seat the pulley -- using the crank threads to pull it on. Plus the "wedge a screwdriver" thing worries me.

My guess is that you did not install the pulley correctly and it is not properly aligned. I would venture to guess that in a few days or weeks, you will shred your a/c belt, then your main belt, and if you don't catch it in time, your pulley will back all the way out. If it does come all the way out, expect some serious damage.

How many miles do you have on it since the swap?
I would put the balancer in the oven first, use gloves Get her nice and hot then she'll go on the crank alot easier expanded. I agree about the screw driver. He should put it in gear, like P3 seeing it is an automatic. You can torque all you want, that crank will not turn, rear wheels on the ground and the E- break too if you like, but not necessary. That way you are not cranking against it in Park. You might screw up the Parking break splines that way.

Last edited by zo6vetteman2003; 09-16-2006 at 12:22 AM.
Old 09-16-2006, 07:35 AM
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The part that bothers me the most was using the balancer and a screwdriver to hold the torque, all the load is going straight into the rubber section for which it wasn't designed. Not sure how much relative movement there was between the inner hub and the outer when you installed it, but elastomer's will experience something called "Mullin's Effect" when you stretch them for the first time after which the elastomer will perform as if it is softer. I don't think the balancer design is such that a large stretch is accounted for in the material design and you may have in effect changed the damping characteristics from those that are desired. I still think you should change it to ensure it is performing its main function correctly, that is damping the crankshaft harmonics.
Old 09-16-2006, 01:54 PM
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I'm glad I found this post. About two weeks ago I attempted the HB install myself with the help of a buddy. Jharms, I'm having the same chirping sounds that seems to be comming from the belts. Later this afternoon I'll do what the rest of the guys in here recommended, remove the belts to see if the sounds remains. Thanks to Connecticut and Vettenuts, I'm putting together my very own HB installing contraption using an extra long bolt, washers and all the good stuff.

One question zo6vetteman2003, is it safe to place the car in P3 and go to work on the bolt? If that is the case, I'm doing it!! I had to remove the exhaust to get to the starter and wedge a small pry bar in there. I really didn't like doing that but I had no choice. I'm also thinking about building a "tool" that won't allow the crank to spin. A version of this tool could be seen here http://ls1tech.com/forums/showthread.php?t=347374. I'll post back with results. Jharms...good luck
Old 09-16-2006, 06:14 PM
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Originally Posted by gmethod
One question zo6vetteman2003, is it safe to place the car in P3 and go to work on the bolt? If that is the case, I'm doing it!! I had to remove the exhaust to get to the starter and wedge a small pry bar in there. I really didn't like doing that but I had no choice. I'm also thinking about building a "tool" that won't allow the crank to spin. A version of this tool could be seen here http://ls1tech.com/forums/showthread.php?t=347374. I'll post back with results. Jharms...good luck
If you have removed the steering rack, and using jackstands, or jacks, use the emergency break, and put the entire weight of the car down on the rear wheels to keep the wheels from turning. Use the E-break whenever you have any wheels off. I chalk the wheels as an added precaution. For a standard, use 4th gear and the E-break with the wheels on the ground. The force needed to move those wheels is incredible.
Are you thinking you would run yourself over? You have alot of hard fast cranking to do then. Are you using a lift? Or in the garage on the floor?

Last edited by zo6vetteman2003; 09-16-2006 at 06:18 PM.
Old 09-16-2006, 06:25 PM
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Actually what I meant was if it was safe for the flywheel, tranny, etc...I'm actually working in my garage. Last time I worked with the HB, I had the car completely in the air since I had to lower the exhaust. This time around I'll just put the tranny in P3, E-brake, a friend holding on to the car, and chocks (you can never be too safe ). Thanks for the advice
Old 09-16-2006, 06:59 PM
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Originally Posted by gmethod
Actually what I meant was if it was safe for the flywheel, tranny, etc...I'm actually working in my garage. Last time I worked with the HB, I had the car completely in the air since I had to lower the exhaust. This time around I'll just put the tranny in P3, E-brake, a friend holding on to the car, and chocks (you can never be too safe ). Thanks for the advice
I saw that tool that you were talking about. On a lift this would work great. P3, the break, chalks, two men and a small boy is fine. It should not hurt the tranny, or drivetrain.
Old 09-17-2006, 09:19 AM
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Jharms
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Originally Posted by Jeff Jeff
It does not sound like you used the proper method to seat the pulley -- using the crank threads to pull it on. Plus the "wedge a screwdriver" thing worries me.

My guess is that you did not install the pulley correctly and it is not properly aligned. I would venture to guess that in a few days or weeks, you will shred your a/c belt, then your main belt, and if you don't catch it in time, your pulley will back all the way out. If it does come all the way out, expect some serious damage.

How many miles do you have on it since the swap?
I've got close to 1000 miles on it since the swap. I took a road trip the weekend after putting it on of about 750 miles. The rest has been around town.

I took belts off last night, as suggested. First the big belt. Same noise. Then the AC belt. The noise went away! I replaced the AC belt last night. The chirping seems to have gone away. I do have a slight noise for a brief moment during acceleration. It may be unrelated...or it maybe related.

I'm not sure about putting the car in third gear and the crank won't move on an automatic. I tried putting it in R but the motor still turned.
Old 09-17-2006, 09:56 AM
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Originally Posted by Jharms
I'm not sure about putting the car in third gear and the crank won't move on an automatic. I tried putting it in R but the motor still turned.
The reason is the torque converter not spinning fast enough for engagement. P3 will not work either then.
Old 09-17-2006, 10:17 AM
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Originally Posted by Jharms
I took belts off last night, as suggested. First the big belt. Same noise. Then the AC belt. The noise went away! I replaced the AC belt last night. The chirping seems to have gone away. I do have a slight noise for a brief moment during acceleration. It may be unrelated...or it maybe related.
I'm glad you isolated the noise. The concern is being able to keep that crank in place. Wedging a screwdriver isn't the greatest method in fear of damage to the balancer, or oil pan, block, and timing cover etc. with that much torque behind it. Do you have the steering rack removed? I have one alternate method that does work. Remove one of the easy access sparkplugs using a piece of clothesline rope, insert into the hole. The rope is above the piston before it reaches TDC. Start cranking the balancer bolt until the crank becomes isolated and this should definitely hold the crank in place. Torque to spec. This alternate method is easy and is widely used during valvespring replacements to keep the valve from dropping into the cylinder. It also holds the crank in place with no damage to the piston.

Last edited by zo6vetteman2003; 09-17-2006 at 10:35 AM.
Old 09-17-2006, 04:11 PM
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Jharms
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Originally Posted by zo6vetteman2003
I'm glad you isolated the noise. The concern is being able to keep that crank in place. Wedging a screwdriver isn't the greatest method in fear of damage to the balancer, or oil pan, block, and timing cover etc. with that much torque behind it. Do you have the steering rack removed? I have one alternate method that does work. Remove one of the easy access sparkplugs using a piece of clothesline rope, insert into the hole. The rope is above the piston before it reaches TDC. Start cranking the balancer bolt until the crank becomes isolated and this should definitely hold the crank in place. Torque to spec. This alternate method is easy and is widely used during valvespring replacements to keep the valve from dropping into the cylinder. It also holds the crank in place with no damage to the piston.
WOW... I wish that someone would have recommended this method of keeping the crank still while torqueing the bolt. It does sound easy. Are you sure it's safe?

To answer your question; no, I do not have the steering rack removed any longer.

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Old 09-17-2006, 05:28 PM
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Originally Posted by Jharms
WOW... I wish that someone would have recommended this method of keeping the crank still while torqueing the bolt. It does sound easy. Are you sure it's safe?

To answer your question; no, I do not have the steering rack removed any longer.
Like I said, it is usually used to keep the valve from dropping during a valvespring change, but isolates the crank also. For an automatic, this method is also used. I forgot about using this method, but yeah it's safe and pretty commonly used. I have a wrench that has a bend on it that can get to the balancer bolt with the rack installed. I've thought about contacting craftsman and have them make it with a ratchet feature and torque wrench handle. You can only get a 1/4 turn with a box wrench before it hits the water pump pulley. I always said, next time I swap my cam, I'll install a two piece timing cover. This saves you from having to remove the steering rack and balancer. Cuts some major time off a cam install.
Old 09-17-2006, 10:28 PM
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Thanks for the help, all! I think my Vette is going to live.
Old 09-17-2006, 10:53 PM
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I had my harmonic balancer replaced at a dealership. I also had a chirp. The new ac belt that I had was not a gatorback belt so I replaced it with one and the problem was gone.

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