Topic: Pulley Wobble
in Forum: C3 Engines
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The crankshaft pulley on my '79 L-48 has a "wobble" to it.
The belt does not (yet) seem in danger of coming off & the motor is not giving any indications of a problem.
I just noticed it.
Does this pulley bolt on to the motor or is it attached some other way?
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There are three bolts that hold the lower pulley to the balancer.
Are you sure it's just the pulley wobbling, or is the balancer also wobbling?
Are you sure it's just the pulley wobbling, or is the balancer also wobbling?
Joel Adams
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If it's the pulley it's probably cracked, if not just need tightening. I had to change one because of a crack where it bolts on and the bolt hole had wallered out. happened a long time ago but I don't think it was a big problem to change out.

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I got a spare 79 pulley in the geeerage if ya need a replacement. Needs cleenin and paintin, but she's solid...

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Be sure to look at the balancer, as Joel suggest.
If the rubber in the balancer is going bad, you could have it come apart and cause a lot of damage. If the pulley is cracked, ditto.
If it's just bent a bit, it may go a long way just like it is, but could chuck a drive belt at high rpm.
I took a better look at it today.
The pulley is tight on each of the three bolts that hold it on.
I couldn't actually see the entire front facing portion of the pulley but I felt around it and did not feel any cracks.
So, could the harmonic balancer be "out of round" ? Gettin' ready to soil the sheets?
You can go ahead and take the pulley and belt off, then take a better look at the balancer. If you're not sure, start the engine with the pulley off and see if it still wobbles. If not, it's just the pulley.
Kyster,
KDADDY79 2008-08-18 17:31:27
Thanks for answering my next question.
I was thinking of removing the pulley but wasn't sure if it'd be ok to start it then.
I'll be able to resume this job next Monday. You all can be sure I'll be back with more Q & A.

Kevin
Today I finally was able to do some work on it.
A friend let me use a lift at his shop, which made this alot easier!
First I started the motor and lifted the car up. The Harmonic Balancer is definitely not wobbling. Only the crankshaft pulley is wobbling.
I removed the belt and took the pulley off. I couldn't see any cracks and it spun nice and round when I spun it on a bolt. One of the three bolt holes is slightly worn, as if its begining to become oval shaped. It took a while to notice this - it wasn't real obvious.
I put it all back together. I torqued each of the three bolts at 60 ft. lbs. ( got the 60 ft. lbs. out of the Chilton's manual. There were no specs for the crankshaft pulley but both the "Crankshaft Balancer Bolts" & the "Flywheel to Crankshaft Bolts" were rated at 60 ft. lbs. So I went with that.)
After restarting the motor the crankshaft pulley still has a noticeable wobble to it but it's not as bad as before.
One of the mechanics at the shop (he seems like a Bubba to me) told me that all crankshaft pulleys wobble. "Don't worry about it!"
Should I worry about it?
in Forum: C3 Engines
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