the crank shaft its harmonic balance?

Trilitheum

I can explain why they get stuck together, they are not fusing. It is a galvanic cell which produces a layer of aluminum oxide on the inner diameter of the pulley.

The aluminum will corrode preferentially to the carbon steel shaft. The problem comes in the volume change when aluminum goes from Al to Al203 (aluminum oxide) the volume increase is about 2 fold.

So if the parts are in intimate contact when they were installed, the oxide layer when formed takes up additional volume and squeezes the inner shaft as it tries to expand with virtually no gap (except the machining tolerance) which is taken up quickly.

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2011 Nissan 370Z Touring/Sport, 6MT, KAD