Harmonic balancer
Team Owner
Joined: Aug 2008
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From: Rochester NY
St. Jude Donor '09 thru '26
Was the flywheel resurfaced and separately balanced? If these three were also not balanced as a unit, and mounted as marked, you may have the source of your problem. 
Dennis
Dennis
Drifting
Joined: Aug 2021
Posts: 1,393
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From: Sacramento, Ca
To answer your question, yes it can be removed in the car. Most of the chain auto parts stores will loan or rent a puller. Other than being able to determine a failure of the vulcanized joint, I'm not sure how removing the harmonic balancer will help in resolving your vibration issue. I would not recommend running the engine without a harmonic balancer in place.
Ted
Ted
Thread Starter
Instructor
Joined: Feb 2022
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Vibration
I don’t intended for run engine without damper.just trying to find source.I don’t know if this will fix the vibration. Fly wheel clutch and pressure plate all new.when I installed them the speed shop said they didn’t think it would madder. Like I said I checked out all my ujoints they were all tight.I don’t want to drive it this way.
Race Director
Joined: Jan 2002
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From: Close to DC
C2 of the Year Finalist - Modified 2020
If your crank snout is drilled, you can use the correct tool to pull the balancer. The speed shop should close up. Balancing the three components can assure you that rotating assembly will spin vibration free. Ask me how I know. Dennis
Dennis
Le Mans Master
Joined: Nov 2015
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From: Really Central IL Illinois
I would recommend prior to pulling the dampner, observe the timing mark with the vacuum plugged, also observe any movement of the outer ring forward and aft. Engine Off: Inspect the rubber at the front and rear of the dampner for bulges and the outer ring for movement when you apply some pressure. Then find TDC with a piston stop and compare the timing mark on the tab with the mark on the dampner.
If the timing is steady and does not flutter, if there are no apparent discontinuities in the rubber, if the outer ring is solid and exhibits no evidence of movement, and the timing marks line up within 2 degrees, your dampner is not likely to be the problem.
If you chose to remove the dampner, the puller rental at the local parts store is the way to go. If you have a HP engine, the crank snout will be drilled and taped. For standard engines installation is with a hammer per the GM Service Manual.
Just my $.02.
If the timing is steady and does not flutter, if there are no apparent discontinuities in the rubber, if the outer ring is solid and exhibits no evidence of movement, and the timing marks line up within 2 degrees, your dampner is not likely to be the problem.
If you chose to remove the dampner, the puller rental at the local parts store is the way to go. If you have a HP engine, the crank snout will be drilled and taped. For standard engines installation is with a hammer per the GM Service Manual.
Just my $.02.
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Thread Starter
Instructor
Joined: Feb 2022
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Engine vibration seems greater at low rpm’s.when I turn it above 2000 rpm’s it seems a lot less.I have been thinking about electric problems.I don’t know what it could be.new plugs and wires carb seems ok.
Le Mans Master
Joined: Sep 2003
Posts: 8,812
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From: eastern NC
What engine are we talking about? SB or BB? HP rating?
Is this a dynamic vibration, or does it occur when the car is stationary as well as going down the road?
At least in this post, you haven't mentioned if any work has been performed on the engine recently. Have any of the dynamic components been changed as part of any recent work?
With the car stationary and the engine idling, focus a light on the harmonic balancer to see if it appears to be wobbling any. If you see any wobble at all it's a good indication that the balancer outer ring has moved out of its original position. Rev the engine a bit while watching the balancer to see if anything changes at all.
Let us know what you discover.
Good luck... GUSTO
Is this a dynamic vibration, or does it occur when the car is stationary as well as going down the road?
At least in this post, you haven't mentioned if any work has been performed on the engine recently. Have any of the dynamic components been changed as part of any recent work?
With the car stationary and the engine idling, focus a light on the harmonic balancer to see if it appears to be wobbling any. If you see any wobble at all it's a good indication that the balancer outer ring has moved out of its original position. Rev the engine a bit while watching the balancer to see if anything changes at all.
Let us know what you discover.
Good luck... GUSTO
Race Director
Joined: Jan 2002
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From: Close to DC
C2 of the Year Finalist - Modified 2020
Please tell all of us who have made helping suggestions based on experience etc, how you NOW know it's the damper? What mechanical work did you do to arrive at this conclusion? 
Dennis
Dennis
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Thread Starter
Instructor
Joined: Feb 2022
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When engine is idling the damper is vibrating.when I bring the rpm’s up to about 2000 damper is smooth. I set valves like the manufacturer said. I was thinking it could be a valve out of adjustment.checked all the spark plug wires to make sure they were right.everything seems to be wired correctly.
Race Director
Joined: Jan 2003
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From: Central Arkansas
A harmonic balances doesn’t balance engine vibration unless it’s an external balanced engine, in which case the harmonic balancer has to have an offset weight. I don’t know much about SBs but I suspect a 408 SB is externally balanced - is it? In that case it should have an offset weighted balancer and flywheel. Did your engine builder balance the entire rotating assembly - engine, flywheel and harmonic damper? If you really believe it’s in the engine/flywheel/balancer assembly, I would be talking to the place that built the engine.