Sampson

I was helping a friend change his timing chain in his '72', 350 a couple weeks ago. After I removed the crank bolt the dampner slid right off the crank with no puller or effort. It does not appear to be loose on the crank but I have never had one come off this easy. Any thoughts on this?

coppercutlass

I have never had a stubborn one. usually a light tap on the outer ring and out it comes.

Lady72nRob71

I bet mine has become one with the crank, judging on how hard it was just to get the pulley off...

oddball

They are supposed to be a press fit, albeit a "loose" press fit. Should require a puller for most of the distance.
There was a rash of dorman balancers that were machined incorrectly and are too loose. The press fit is required for the balancer to do its balancing correctly.

BILL DEMMER

and then there's the sealer that's supposed to be between the nose of the crank and the balancer hole. i did have a '64 330 that i was disassembling years ago, the balancer came right off in my hand as i was moving the engine stand. as i recall, the early 330's weren't a slight press fit or taper fit, just straight on.


bill

Sampson

Sealer?????????
What kind of sealer?

cutlassefi

How so?

MDchanic

I have wondered this as well.

My current "junkyard" engine has a looser balancer fit than others I have disassembled (just needed a light pull), but it seems to me that the 200 or more foot-pounds of torque on the bolt keep it pretty firmly attached.

- Eric

455man

I've had two engines that had loose pulleys. Starting to think it's an Olds thing.

rjohnson442

My new doorman one slipped right on and off by hand. works fine and seals completely. I needed a puller and installer for the stock one.

joe_padavano

It's actually not balancing, it's damping torsional vibrations in the crank, and yes, tighter is better. The torsional damping is done in the rubber between the inner and outer rings. A tight fit between the balanc... er, DAMPER and the crank ensures that the torsional energy is properly coupled into the damper. Looseness between the damper hub and the crank prevents this coupling and can result in greater torsional loads in the crank.

Octania

Well put, Joe P.

While the tight pinch from a properly torqued balancer bolt is good, it's no comparison to the marriage of snout and hub that you get with a proper press fit.

In the several dozen Olds V8's I have dismantled, I have had anywhere from "fell off" to "broke the puller"

Normal manufacturing variances.

Some small amount of sealer helps keep oil from seeping out the crevices.

joe_padavano

This has been my experience as well, but I have to say that the earlier the motor build, the looser the fit. Don't know if this is a learning curve on the part of Olds engineers, or simply my failing memory.

cutlassefi

Joe, you still didn't explain this, nor did he for that matter. He says for it to balance properly, nothing about harmonics.

joe_padavano

I agree, Mark. As noted, the press fit is not required for balancing.

BILL DEMMER

i use hi-tack or indian head. this is used to prevent oil seepage from between the balancer/damper/dampener/whatever and the snout of the crank/crank keyway. i just put a thin coat of sealer on the i.d. of the balancer/damper/dampener/whatever covering the front half inch. i use a little dab or so on the key, too. one additional note: when you torque the snot out of the balancer/damper/dampener/whatever bolt, it forces the key against the balancer/damper/dampener/whatever key slot (notice the taper in the key way on the crank-it gets shallower the further back it goes). the '67 csm specs. the mega-bolt at 180 ft/lbs min. i think that would create a nice coupling between the crank and balancer/damper/dampener/whatever.


bill

scott_442

Not much here that hasn't already been stated except the part about using Loctite 609 retaining shaft compound to compensate for the looseness. This information was received from a specialist in rebuilding HB's.


The harmonic balancer is like a tuning fork, tuned to a certain frequency, to dampen the twisting vibration of the crankshaft. When the rubber ages, it changes frequency and no longer absorbs the twisting vibration of the crankshaft. When that is not absorbed, the vibration begins to damage other parts of the engine. Such as the inside diameter of the crankshaft harmonic balancer. To check the condition of the rubber in the harmonic balancer, push your thumb nail into the rubber strip. It should feel like a firm rubber, but not so firm as to hurt your fingernail, when it sort of moves, but hurts the thumb nail in the process, it has already hardened past being of use to the engine. From there it can turn into a hard plastic mass that makes the unit totally useless. The repair is to replace the rubber strip or find a NOS unit to replace. The sleeve on the oil seal can be had from a good auto parts supply house. The loose inside diameter can be compensated for by a coating on the inside diameter of Loctite 609 retaining shaft compound on assembly.

www.hbrepair.com

coppercutlass

This might explain why the short block I picked up had rtv on the front end of the crank snout. I have never used any sealants but never had leaks fron the front. Although I do like bill demmers recommendation .

BILL DEMMER

i got it from the csm.


bill

jfb

I heard that loc tite makes a kit> I heard to make it fit more tightly or maybe a sealant check it out online.