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Harmonic balancer screamed then fell off!

HenryKrinkle

NAXJA Forum User
Location
WI
Well, I fired up the '88 today after replacing the manifold and a bunch of other stuff. It ran fine for a while, then started making this horrible screeching sound that I thought came from low near the firewall. Then the outer half of the harmonic balancer fell off with the belt.

Did I overtighten the belt? Is this something that happens often? It seems to me like a part like this shouldn't ever really fail. Can I get this one repaired or just replace it? Could this have damaged the engine in any way? There was nothing visibly wrong with the belt system afterward even though the metal fan made contact with it after it fell off.

My manual says to use a special puller to avoid damaging the balancer. At this point I would consider it damaged, so can I just use a normal puller tool? The installation seemed pretty straight-forward: remove the bolt while holding the crankshaft in place, pull it off, tap on a new one, replace bolt.

Anyone have any help for me here? Is this as simple of a fix as I hope? Could I have damaged the motor in any way? Any guesses what caused it to fail?

Thanks a bunch.....
 
Yep, I've actually done two with the fan and radiator in place. It does make it a little easier to see if the bumper is not on, but it is not necessary.


Well, I fired up the '88 today after replacing the manifold and a bunch of other stuff. It ran fine for a while, then started making this horrible screeching sound that I thought came from low near the firewall. Then the outer half of the harmonic balancer fell off with the belt.

Did I overtighten the belt? Is this something that happens often? It seems to me like a part like this shouldn't ever really fail. Can I get this one repaired or just replace it? Could this have damaged the engine in any way? There was nothing visibly wrong with the belt system afterward even though the metal fan made contact with it after it fell off.

This part does fail, and it is not repairable. It is around $70 for the balancer, which is not bad.

My manual says to use a special puller to avoid damaging the balancer. At this point I would consider it damaged, so can I just use a normal puller tool? The installation seemed pretty straight-forward: remove the bolt while holding the crankshaft in place, pull it off, tap on a new one, replace bolt.

Still need the puller, and you should not tap a new one on. You get a longer 1/2-20 bolt, a nut, and the original washer. Thread the nut and the washer onto the bolt, then slip that through the new balancer and thread it into the shaft. Make sure the bolt is in a good way, then start cranking down on the NUT, not the bolt, point being that the tightening of the nut on the bolt is what seats the new balancer, rather than the bolt into the threads in the shaft. This eliminates the posibility of stripping the threads in the shaft.

Anyone have any help for me here? Is this as simple of a fix as I hope? Could I have damaged the motor in any way? Any guesses what caused it to fail?

It is a simple fix, motor should be fine, and it failed due to time and aged rubber.

Thanks a bunch.....
 
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i had a very bad scream coming from the bearing of the waterpump before. When you press the thottle you could see the belt moving like crazy because of the bad bearing. I would inspect that area as well when you put a harmonic balancer on. Best of luck.
 
Since the belt is off, definitely give everything a spin by hand to see if it sounds/feels okay. While you've got the balancer off, there is a oil seal behind it that you should consider replacing. Usually called the front main seal, or the front crank shaft seal.

Borrow or rent a puller. Don't use the stock bolt right to pull the new balancer on unless you have plenty of thread engaged. Otherwise, you'll strip the threads right off and then you'll be screwed. Get a longer bolt than stock a nut and a few washers. Thread the bolt all the way in and use the nut and washer to do the pushing.
 
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