OOOPs, sorry about that, I know that there is not a crank nut. There is a bolt.

I didn't say that it would get loose on its own. I said that if you put it toegther loose you'll have problems.

If you don't torque the bolt, the pulley will be loosen on the crank and once that happens, it will start to move back and forth, as the crank stops rotating. Then, it will get worse and worse. Eventually, it will be loose and it will be rocking back and forth. Then, it will wallow out the key-way on the pulley and the crank.

You are correct it won't happen over night. It will take many thousands of miles for it to happen. You might not ever notice it, but when you go to take that T-chain off, you are going to wonder....what happened here?

The pulley will not get loose if you don't torque the crank bolt. The balancer may or may not, depending on how far it's pressed onto the crank snout. The crank pulley is bolted to the balancer via 4, 3/8" bolts.