Crankshaft/harmonic balancer on a 1992 Buick Century: diagnosing, removing, fixing


#1

Your help is needed and much appreciated with the following. The current symptoms are (this 1992 Buick Century 3.3L has everything on one long serpentine belt):

1) noise;

2) with the engine not running, I can move the belt some distance up or down until something bangs on something (metal on metal; sounds close to the noise, only a single bang);

3) with the engine running and the belt on the noise is the worst when idling; it seems to go away when I press on accelerator (no matter in park or drive shift) and to get worse if i turn the steering wheel;

4) with the engine running and the belt off (only for a few seconds not to overheat) the noise is still there, similar but less loud, so it is definitely not any other pulley on the belt.

I want to try fix it myself. I have found some advisory about using a special tool, the puller, Part #J38197, at

http://www…icles.html

(it is there under CRANKSHAFT DAMPER CAUTION ON 1991-93 3.3L VIN N)

which concerns me since they say ``Failure to use the correct tool while removing the

damper may cause damage to the one piece balancer/damper assembly."

So, if you could please help with the following questions:

1. Given the above symptoms, is it the balancer?

2. Can I still do it if I do not have that special ‘puller’?

3. Can it be fixed by welding in any condition? In my case it only started last week, so about 200 miles ago.

4. Is it a simple welding around the whole thing or does it require any kind of balancing and/or creating a weld in some precise location?

I just have no idea what’s inside the thing and how it is supposed to be but I should be able to find someone who will weld it for me.

Thanks much again!


#2

The puller isn’t that special. You could make it (or, perhaps, buy one at an auto parts store). It’s a flat piece of steel with three holes for the pull bolts, and a center hole for the push bolt.


#3

It certainly could be the harmonic balancer. Most have a rubber insert as the damping agent, so welding is out of the question if you want to retain function.


#4

Thanks for the info! The reason why I mentioned welding is that I had seen someone writing about it in another thread (I quote):

“Personally, I have pulled dozens of those pulleys off, welded the pulley to the fly weight and put the car back on the road charging 1 hour flat rate and never have had a failure… But if operated too long the wear will preclude this repair.”

If you could give a kind of second opinion on this, that would be great because I am lost now as to the construction of a balancer assembly: where is what inside the thing?


#5

Welding won’t work. The rubber is actually an integral part of the balancer’s function.

Each time a piston fires, there’s a rotational force applied to the crankshaft, a pulse if you will.

As the rotational pulse happens, some energy is stored in the rubber. The rubber then releases the energy by pulling the other 1/2 of the mass along behind it, converting that energy into inertia in that then-rotating mass. As the acceleration of the mass is rising, the initial rotational pulse is falling. The inertia in that rotating mass provides pulses back into the balancer 180 degrees out of phase with the initial pulses.

That’s why it’s called a harmonic balancer. It feeds input into the rotating shaft out of phase with the initial input and reduces the amplitude of the pulsating energy wave effectively in half, sort of smoothing things out.


#6

This accelerating mass theory you describe must be from the Einstine works that are just now being made public. Gosh, where can I find that?

Many General Motors engines incorporate an harmonic balancer which has the pulley pinned to the balancer. If the pin breaks, the pulley sweeps back and forth hammering against the weight. If not quickly repaired the pulley will wear and no longer remain concentric on the weight and the belt will be thrown off. If the pulley/balancer is removed and the two pieces remain concentric the weight can be tacked to the pulley with great success… Many repairs NO COMPLAINTS from the customers.


#7

Remove tension from the belt. If you can rock the harmonic balancer back and forth (fore and aft), either the rubber between the two parts has broken, or the large center bolt has become loose. If the hole (3/4 inch) has enlarged, you can tap it to 20 mm (yes, metric). Carry the bolt with you to the tool supplier for the next metric size larger. The crankshaft is too hard to go to the next larger inch size. I have done it.


#8

Not Einstein, but basic physics, specifically the clear definition of conservation of energy and the basic understanding of inertia.

Of course, you can always stick to your ‘red-neck’ engineering.


#9

Nothing succeeds quite like success… I have repaired dozens with no failures. And I am an ASE Master with many years experience, red-neck and all.


#10

I’m happy that it’s worked for you, but when you do that you’re essentially turning the harmonic balancer into a plain ol’ pulley.

I have nothing whatsoever against rednecks. The ones I know are good folks. One particular couple I know, she’s visually handicapped and in the process of getting her umpteenth college degree and he’s a career military man. They are two of the kindest, humblest, most decent people I’ve ever known.


#11

For any interested in the facts, they might take the time to inspect the harmonic balancer from the engine being discussed and then rethink the situation.


#12

Now why would we want to confuse ourselves with facts? ;o}

Anyone have a picture of this piece?