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Old 10-23-2011, 05:03 PM   #1
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Join Date: Jun 2001
Location: Benton, AR "The Heart of Arkansas"
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'91 4.3 question - harmonic balancer

My son has a '91, with the 4.3/automatic. I think his harmonic balancer is bad. When the engine is cold, it is quiet. When it has warmed up, there's a knocking sound that isn't a bearing. I'm thinking the balancer is the source of the noise. He's down on money, so I'm trying to offer free suggestions so he won't do something stupid...well, anything else stupid.

Any easy way to know that the balancer is the issue?
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'96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed.

'69 C-10 SWB; 350/TH400 - in limbo

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Old 11-15-2011, 03:11 PM   #2
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Re: '91 4.3 question - harmonic balancer

I doubt the balancer is the cause. cracked flexplate?
a rod knock can be confirmed by shorting one cylinder at a time. when it stops you have found the bad rod.
Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card
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