Oil leak from front seal on timing cover 4.3l

chartersj

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May 14, 2013
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It appears that the bottom oil seal on my timing cover is bad and was wondering if anyone has changed the seal only and not the whole plastic cover? I would rather not have to pull the motor and oil pan just because of a bad seal. Parts diagrams shows you have to buy the whole cover and the seal is already in it. Could you buy a new cover and pop the seal out to change over?
 

chartersj

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More likely its cracked,

I have yet to pull the harmonic damper but I just changed out a pre-vortec motor for a vortec last summer, and I used the old harmonic damper instead of the one that came with the new motor, so im thinking I didn't clean the seal surface on the old damper and took out the seal.
 

Bondo

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and I used the old harmonic damper instead of the one that came with the new motor,

Ayuh,.... Why did ya do that,..??

Harmonic balancers are balanced to the motor's rotatin' assembly,...

The 4.3l has gone through many incarnations, none of which are exactly the same,...
 

chartersj

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I used the old damper because it accepted the original v belt pulley. The damper on the vortec motor had a lip on in and the pulley wouldn't sit flush where it came with a serpentine pulley.
 

chartersj

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Ayuh,.... Why did ya do that,..??

Harmonic balancers are balanced to the motor's rotatin' assembly,...

The 4.3l has gone through many incarnations, none of which are exactly the same,...

I also used the flywheel off the old motor so the coupler would bolt to it, which was much heavier then the automotive flywheel that came on the vortec. So by changing that out also, wouldn't that throw the motors rotating assembly off as well?

I found an oem part number 10128316 which changed to 296-15 and have that on order. Pulled the balancer today and the seal surface has some pitting on it which must have been the culprit.
 

Bondo

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So by changing that out also, wouldn't that throw the motors rotating assembly off as well?

Ayuh,.... I'm surprised the motor ain't shakin' itself outa the hull,....
 

chartersj

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Ayuh,.... I'm surprised the motor ain't shakin' itself outa the hull,....

I was concerned with that as well but its nice and smooth. I got all the info how to do the swap on here as I'm not the first to do this with success
 
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