Harmonic Balancer off 180?

[Shawn's 78]

So i go to time the motor last night, found the timing mark, gave it some color and fire up the motor to check the timing.

Well get this; my mark wasn't visible, but another mark set by someone else (?) :confused was showing up. Is it possible that the harmonic balancer is off 180 and this is what is causing some of my engine vibration??? :confused :confused
Am i ok to leave the the balancer as is or should i move it back to the original location??
Shawn

 

[vette-dude]

Suggest you replace the harmonic dampener if there is any doubt that it is defective. If you don't, eventually you will break the crankshaft just behind the second rod journal. The dampener is relatively inexpensive at local aftermarket parts stores. If you are really winging the motor, you might entertain buying a high performance fluid dampener (read as more expensive). Make sure you get the correct dampener for your motor. Oh yeah, don't beat it on. Use the front crank bolt and ease it on. Put a tension on it and using a rubber hammer tap it a little at a time as you tension the crank bolt. Takes awhile so don get frustrated and pick up the big hammer and beat the h*** out of it as you will ruin the new dampener and possibly the thrust bearing on the crank. Take your time and do it right! See ya.

 

[Jack]

distributor 180º out

Suggest the distributor is installed 180º out. All dampers I've seen for sbc have only one keyway & crank has only one keyway ... so damper installs in one position only.

Another possibility is the damper's rubber has failed & outer inertia ring (where OE timing mark is) has slipped ... but I've never seen one slip as far as 180º without catastrophic/obvious damper failure.
JACK:gap

 

[Jack]

look at damper first

Since my post above, I've reviewed your previous posts re: vibration. I now suggest you first focus on damper. If you remove damper, do install a new seal in the timing cover before you replace damper.
JACK:gap

 

[vigman]

Er Jack

If the distributor is 180 degrees out the car will not run.


Vig!

 

[JohnZ]

Re: Er Jack

If the distributor is 180 degrees out the car will not run.


Vig!

True, unless some Bubba installed the distributor 180-out and re-indexed the plug wires to match, in which case if you put your timing light on what's supposed to be the #1 wire, it will actually be the #6 wire, and the original timing mark will be exactly 180-out when the light fires - I've seen two of these beauts!

I've never seen a balancer outer ring slipped more than 10 degrees without coming off completely.

NOT a good idea to use the balancer bolt to install a balancer; strip it and you're in a world of hurt! Use the correct tool (which you can rent from any auto parts store) or get a length of 7/16"-20 allthread, remove the bolt, install the allthread, and use oiled washers and a 7/16"-20 nut to pull it on, then install the balancer bolt when you're done.

 

[vigman]

Well you are correct John

I made the mistake of assuming that the cap was pulled and #1 was verified...DOH!


Which would stand to reason why there is a second timing mark! ( DOUBLE DOH!)

I TRY NEVER TO CONSIDER THE BUBBA FACTOR

It's just to horrible to contemplate


Vig!

 

[Jack]

Re: Well you are correct John

I TRY NEVER TO CONSIDER THE BUBBA FACTOR
Vig!

I do ... I'm the living embodiment of Bubba (hence :gap) ... plus Shawn's post (extra timing mark) tipped me.

BTW, locally I couldn't find a long enough bolt with threads all the way. My local parts stores lend the tool to pull the damper ... but none had even heard of the install tool. So I ordered one from Proform ... it was delivered as defective. While waiting for resolution, I ordered a pro setup from BHJ dampers ($$) that I like a lot. Original was replaced under warranty, so now I have two ... don't need but one. I used the replacement just to verify it is OK so it's like new ... it has thrust bearing and its double-end fits both sbc & BBC. Anyone need it? ... I'll take $30 for it.
JACK:gap

 

[Shawn's 78]

I'm fairly sure that it is the balancer. The outer ring won't hold a mark for TDC. I also did research on old invoices from owners past and noticed that someone had tried to give it a tune, "unable to tune, balancer had moved". That was back in '97. Thank God there has only been 2k miles put on it since then. This may also account for the flucuation in vibration i am feeling; sometimes worse than others.

I think the safe bet would be to replace the balancer without question. Any suggestions? OEM, High pro or general aftermarket?

Jack - if you still have that installer, let's talk. I'm sure i'll need it!

Shawn:cool

 

[Jack]

I'm fairly sure that it is the balancer. The outer ring won't hold a mark for TDC. I also did research on old invoices from owners past and noticed that someone had tried to give it a tune, "unable to tune, balancer had moved". That was back in '97. Thank God there has only been 2k miles put on it since then. This may also account for the flucuation in vibration i am feeling; sometimes worse than others.

I think the safe bet would be to replace the balancer without question. Any suggestions? OEM, High pro or general aftermarket?

Jack - if you still have that installer, let's talk. I'm sure i'll need it!

Shawn:cool

Shawn:
Just think ... you've probably got the original damper ... and it lasted about 20 years. IMHO, go back with OEM from chevy or OE-replacement from parts store. Unless you're gonna race every weekend, an SFI/PRO damper isn't needed. Look at today's chevy hi-po crates ... they come with elastomer-rubber damper ... like what came on yours 25 years ago. So long as you keep engine degreaser/oil/other petro-chem solvents off the new OE damper's rubber & NEVER, EVER pry on its outer ring ... it'll do ya proud. Again, replace timing cover seal. Lemme know if ya want the damper install tool?
JACK:gap

 

[Shawn's 78]

Jack,
No need for the install tool, the remover i picked up had an installer included. Thanks anyway.

As for the balancer, no problems coming off or putting back on, and man can i tell you how shot :eek the original one was. I could almost push the outer ring from the inner ring with just my hands! After all said and done, I noticed a differance in engine vibration and I was finally able to turn her in :L.

As for the vibration around 3200 rpms, pretty sure it is the clutch. That will be my next project.
Thanks everyone for your help on this one!
Shawn

 

[Jack]

man can i tell you how shot :eek the original one was. I could almost push the outer ring from the inner ring with just my hands! After all said and done, I noticed a differance in engine vibration and I was finally able to turn her in Thanks everyone for your help on this one!Shawn

Shawn:
With damper ring that badly slipped ... you're one lucky fellow it didn't tear up abuncha other stuff! Glad it worked out so well. Should be a piece of cake to set ig timing now. Hope you find as much luck chasing the 3.2K vibration.
JACK:gap