# 1965 GTO Harmonic Balancer Question



## propuckstopper (Jan 20, 2012)

Hi folks. I hope all is well. I am just in the middle of cleaning up and detailing my 1965 GTO engine compartment. I have removed the harmonic balancer (2 groove pulley, cup, and "inertia" ring) from the engine and have found the rubber insulator to be in great shape.

I carefully cleaned everything up and repainted the correct shade of engine blue.

My question is: I did not scribe the inertia ring relative to the cup upon disassembly. Does it matter how they go back together, in terms of "clocking"?

Everything I have read states that most Pontiac harmonic balancers are "zero-balanced", but I can't say that I fully understand this relative to my reassembly process.

Any ideas?

Thanks!


----------



## BearGFR (Aug 25, 2008)

Ifn' it were me, I'd replace it completely. If you were able to get it apart, then there's a chance it'll be able to do that again by itself at say, 5000 rpm and that's something you definitely don't want bouncing around in your engine compartment. Also, the consequences of getting it back together wrong will be that your main bearings will die an untimely death. I'd never take the chance, but that's just me.

Bear


----------



## olde-goat (Feb 1, 2009)

*Balancer*

When I rebuilt the 389 for my 65 GTO I was told by more than one source never to reuse the old balancer. Apparently they deteriorate with age but cannot be detected upon visual inspection. An old balancer can cause problems. A rebuilt unit from Damper Doctors was only a couple of hundred dollars. Relatively cheap part on a very expensive engine rebuild. Just my 2 cents...


----------



## geeteeohguy (Feb 2, 2008)

I've re-used the old ones in the past because there were no other options. (1980's overhauls). I've been lucky. I'm not sure if you're talking about simply unbolting the pulley, or if you removed the center section of the balancer. If the latter, get a new one. I think if I were to do another engine, these gents make good sense: replace it with a new part. It's cheap insurance. 47 year old rubber is, well, 47 year old rubber!!


----------

