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Installing Harmonic Balancer with no thread in crank on OMC

T

tdwaters

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1987 3.0L model 302AMFTC
How hot can you get a new hamonic balancer without damaging rubber insert? My Crank is 1.25" and new balancer seems to have about 0.003 press. I tried heating the old balancer up to 300F and it would not tap on. If I pull the crank I guess I have to install part in press with tiing gear cover in between?​
 
I am tempted to, but that would not be so good for the crank bearings. I think you were working on someone elses boat or are making a funny.
 
Ayuh,.... You shouldn't have to heat it at all,.....

Did ya clean the crank with emery cloth,..??

Isn't there bolt holes on the front of the block, like 4 3/8" bolt holes, 2 on each side,..??

Bridge those holes, 'n use a threaded rod to press on the balancer hub,...
 
There is not thread in end of crank to pull against, just a machined taper. There are 3 holes in timing gear on crank directly behind harmonic balancer, but the timing gear cover and seal are mounted between gear and balancer?? Maybe with oil pan off I could c clamp the crank shaft to the block in some way.
 
Ayuh,..... On the face of the BLOCK, ya mount a bridge,....

Through yer bridge, ya use a threaded rod to Push the hub on,.....

The threaded rod pushes against the Hub, 'n the Bridge, no center hole needed,....
 
I have also drilled and tapped for a 7/16 fine thread in that type crankshaft. Most marine cranks are steel and not cast, so they are nice to work on. Even with the above mentioned procedure, you can put a hell of a force on the thrust bearing.......you likely won't hurt it if the harmonic is properly sized, but in order to really be sure, I like to have my harmonics bolted on when I am done. Marine engines really go through hell.
 
If this engine is not yet installed, why not drill the center of the crankshaft and make female threads?
Had threads been OEM, the factory would have used rolled threads in lieu of cut threads..... as rolled threads are stronger.

Even with rolled female threads, they should NOT be used for rotational force pulling.

You would use the correct installation tool for this.

This tool has two different crankshaft thread sizes.... the one that fits would be fully threaded into the crankshaft.
The large nut, thrust bearing and washer (that do the actual work) can be reversed.

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tdwaters said:
I don't suppose we are talking about drilling and tapping with crank in engine? Pull the crank and take to a shop?
Click to expand...

See my first sentence in post #8!

A machine shop will be able to stand the engine vertically on the rear crankshaft flange.
They will figure out a method for drilling and making threads.


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