Engine Rebuild

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Darren 72

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Jul 14, 2010
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NH
My Car
1972 Mach 1
Hey Guys,

Just looking for some advice. I replaced the keyway on the crankshaft and now I can't get the harmonic balancer on. Should I file the keyway down? Its way too tight.

Thanks

D. Rolls

 
Hey Darren. When I was re-installing the Harmonic Balancer after the rebuild, it seemed like I had to crank that sucker down forever. I wouldn't think about shaving anything until it seems like you're pulling the crankshaft out as you snug it in. Post back here at that time and we'll see where you're at.

 
Hey Darren. When I was re-installing the Harmonic Balancer after the rebuild, it seemed like I had to crank that sucker down forever. I wouldn't think about shaving anything until it seems like you're pulling the crankshaft out as you snug it in. Post back here at that time and we'll see where you're at.
I cant even catch any threads at this point. I gently tapped with a rubber mallet but I think this may not be a good idea so I really don't want to take that approach.

Thanks

 
Hey Darren. When I was re-installing the Harmonic Balancer after the rebuild, it seemed like I had to crank that sucker down forever. I wouldn't think about shaving anything until it seems like you're pulling the crankshaft out as you snug it in. Post back here at that time and we'll see where you're at.
I cant even catch any threads at this point. I gently tapped with a rubber mallet but I think this may not be a good idea so I really don't want to take that approach.

Thanks
OK. I'm trying to envision what you've got but it seems strange. I'll look for others to post up with a better memory than mine. :s

 
Did you tilt the key just slightly down in the front so the balancer starts?
Yes. It starts but only goes 1/2 way on. I may try the heating trick. I will also measure the keyway and the slot in the balancer and check height of the keyway.

Thanks

 
The balancer is a slight press fit. It requires a longer bolt or a balancer install tool to get it on properly. I would be hesitant to use heat with the rubber ring in there you do not want the rubber to delaminate.

 
The balancer is a slight press fit. It requires a longer bolt or a balancer install tool to get it on properly. I would be hesitant to use heat with the rubber ring in there you do not want the rubber to delaminate.
I don't think heat would work anyway...it would make the key slot tighter as well. Sounds to me like the key is either the wrong size or misaligned. As for the longer bolt...I have done that but stripped the threads inside the crank so DO NOT try to press it on with the crank bolt. use a block of wood and BFH with the bolt pulling it in at the same time. Don't hit it on the outside, and don't hit it hard or you will damage the thrust bearing.

 
Last edited by a moderator:
Boiling temperature of water is 212deg F.

Normal Engine operating temp is approximately the same.

Metal expands with heat making the key way wider, allowing it to go on easier.

I have done this before with no issues.

 
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