Dead-Blow hammer and offer a little persuasion to get it started, then add the washer and bolt.

 

Thank you.

 

be careful beating on it, I did that once to a chevy I had, factory gm balancer, new radiator, hoses etc. got it on, started it up and it exploded, took out the radiator and cut the bottom hose. Chevy would only replace the balancer, I had to eat the radiator and hose. I would recommend finding a longer bolt.