Worst fears confirmed
Thread Starter
Racer
Joined: Jan 2014
Posts: 407
Likes: 14
From: Mulberry Florida
Worst fears confirmed
My balancer has slipped. It looks like about 3 inches or more. I got the number 1 pistion on top dead center made a white mark on the balancer at zero on the tab. Checked that the rotor was under the number 1 plug wire on the distributor, which it was. Set the timing light to 8 BTDC and the mark was dead on zero with the engine running. Now for my question my car is a 76 l82 the balancer is quite large, I assume it is an 8 in. It is 2 in. thick. I have not ever changed a balancer pulled and put back on in the old days. The question I have is there a replacement the same size. I have heard guys here that have done some work on their car and had broblems with the pulleys not lining back up. I have tryed google to see if I could find measurements on balancers from the face to the end of what I call the snout, for lack of other term. I just don't what to get into a problem when I put on a new balancer and the pulleys not line up with the top pulleys, because the new ones are not as thick. Sorry for a long post, just wanted to give as much info as I could. Thanks
Lawrence
Lawrence
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
I think you are jumping to conclusions. If you are showing a zero w/ timing light and you wanted 8, I don't see where that is three inches. More like a half an inch.
Somethings to consider:
Timing tab marks on the timing cover correct or bent?
Was Vac hooked up to dizzy?
What RPM did you get zero degrees?
Creditabilty of the timing light?
Somethings to consider:
Timing tab marks on the timing cover correct or bent?
Was Vac hooked up to dizzy?
What RPM did you get zero degrees?
Creditabilty of the timing light?
Le Mans Master
Joined: Aug 2005
Posts: 6,521
Likes: 1,956
From: Temple Terrace Florida
Balancer
I don't know if your balancer has slipped or not. If you confirm it has, remove it and send it to Damper Dudes in Cali. They can rebuild your original in less than a week. All will go back together as original. I had them rebuild the balancer on my 66 and 68 small blocks. Good luck. Jerry
Thread Starter
Racer
Joined: Jan 2014
Posts: 407
Likes: 14
From: Mulberry Florida
I think you are jumping to conclusions. If you are showing a zero w/ timing light and you wanted 8, I don't see where that is three inches. More like a half an inch.
Somethings to consider:
Timing tab marks on the timing cover correct or bent?
Was Vac hooked up to dizzy?
What RPM did you get zero degrees?
Creditabilty of the timing light?
Somethings to consider:
Timing tab marks on the timing cover correct or bent?
Was Vac hooked up to dizzy?
What RPM did you get zero degrees?
Creditabilty of the timing light?
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
Yes the L82 uses an 8" harmonic damper. Yes there are replacements. You can buy one for as little as $40.
https://www.summitracing.com/ga/search/part-type/harmonic-balancers/make/chevrolet/engine-size/5-7l-350/engine-family/chevy-small-block-gen-i/engine-balance/internal/outside-diameter-in/8-000-in?N=4294943542%2B4294951398%2B429495138 8%2B4294951379%2B4294949313%2B4294903482 &SortBy=Default&SortOrder=Ascending&reta illocation=ga
Will
https://www.summitracing.com/ga/search/part-type/harmonic-balancers/make/chevrolet/engine-size/5-7l-350/engine-family/chevy-small-block-gen-i/engine-balance/internal/outside-diameter-in/8-000-in?N=4294943542%2B4294951398%2B429495138 8%2B4294951379%2B4294949313%2B4294903482 &SortBy=Default&SortOrder=Ascending&reta illocation=ga
Will
Last edited by rklessdriver; Apr 6, 2018 at 06:01 PM.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
Another possibilty, but really remote is, the key on the crank snout is missing, damaged, etc. In a sense then the vibration damper did slip but it would be the whole unit.
The outer ring of dampers do on occasion slip, but its pretty rare. And to verify that, would require a piston stop tool in the sparkplug hole and some extra work.
You are still confusing the dizzy rotor location with actual TDC mark on the damper. Those two things could be off because of slop in the timing chain or incorrect location of the dizzy itself.
Also, is this the original timing tab on the original timing cover?
The outer ring of dampers do on occasion slip, but its pretty rare. And to verify that, would require a piston stop tool in the sparkplug hole and some extra work.
You are still confusing the dizzy rotor location with actual TDC mark on the damper. Those two things could be off because of slop in the timing chain or incorrect location of the dizzy itself.
Also, is this the original timing tab on the original timing cover?
Last edited by HeadsU.P.; Apr 7, 2018 at 06:17 PM.
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Thread Starter
Racer
Joined: Jan 2014
Posts: 407
Likes: 14
From: Mulberry Florida
Another possibilty, but really remote is, the key on the crank snout is missing, damaged, etc. In a sense then the vibration damper did slip but it would be the whole unit.
The outer ring of dampers do on occasion slip, but is pretty rare. And to verify that, would require a piston stop tool in the sparkplug hole and some extra work.
You are still confusing the dizzy rotor location with actual TDC mark on the damper. Those two things could be off because of slop in the timing chain or incorrect location of the dizzy itself.
Also, is this the original timing tab on the original timing cover?
The outer ring of dampers do on occasion slip, but is pretty rare. And to verify that, would require a piston stop tool in the sparkplug hole and some extra work.
You are still confusing the dizzy rotor location with actual TDC mark on the damper. Those two things could be off because of slop in the timing chain or incorrect location of the dizzy itself.
Also, is this the original timing tab on the original timing cover?
Tech Contributor
Joined: Aug 1999
Posts: 14,373
Likes: 6,370
From: At my Bar drinking and wrenching in Lafayette Colorado
You can't determine TDC using the method you used - you're not anywhere close on your accuracy. You need to use a piston stop and do it accurately. Drop me a note for my "TDC Tech Paper" for instructions on how to determine TDC with accuracy. Only then can you determine if the balancer has slipped.
Lars
V8FastCars@msn.com
Lars
V8FastCars@msn.com
Last edited by lars; Apr 6, 2018 at 06:49 PM.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
There are a few aftermarket timing tabs that supposedly bolt to the timing cover using the existing bolts. How accurate those pointers / number scales are can only be determined using a piston stop. In a nutshell: they can't be trusted out-of-the-box.
As you can see, posters on here are quick to replace a harmonic balancer without checking for actual defects. And I sure wouldn't purchase or install one for $40. I value my hood, mine and others personal property.
Now, your non-confirmed fears are the worst.
As you can see, posters on here are quick to replace a harmonic balancer without checking for actual defects. And I sure wouldn't purchase or install one for $40. I value my hood, mine and others personal property.
Now, your non-confirmed fears are the worst.
Last edited by HeadsU.P.; Apr 6, 2018 at 08:19 PM.
Thread Starter
Racer
Joined: Jan 2014
Posts: 407
Likes: 14
From: Mulberry Florida
You can't determine TDC using the method you used - you're not anywhere close on your accuracy. You need to use a piston stop and do it accurately. Drop me a note for my "TDC Tech Paper" for instructions on how to determine TDC with accuracy. Only then can you determine if the balancer has slipped.
Lars
V8FastCars@msn.com
Lars
V8FastCars@msn.com
Thanks again Lars
I will send you a private message
Tech Contributor
Joined: Aug 1999
Posts: 14,373
Likes: 6,370
From: At my Bar drinking and wrenching in Lafayette Colorado
Send me an e-mail for info - I don't check all the "PMs", "IMs", and whatever it all is on all the Forums I contribute to - it would be a full time job. Drop me a note if you need some assistance. 
Lars
V8FastCars@msn.com
Lars
V8FastCars@msn.com
Instructor
Joined: Sep 2017
Posts: 169
Likes: 20
From: Westlake Ohio
Lawrence, are you sure that's not the groove for the magnetic timing probe vs TDC. Also if you dial your timing light to 8 degrees then the mark will be at zero. If your light is set to zero then the timing mark will be at 8 degrees. Also I would check the timing chain for stretch. Before condeming the balancer. Better safe than sorry.