[Grumpy old man]

Did you heat the balancer and cool the shaft before trying to install it ? Slowly heating the balancer in water until boil and packing the shaft in ice for an hour really helps to ease install , carry it out to the truck in the hot pot ,remove the packed ice bags use some spray lube line up the keyway using heavy gloves and using a short section of 2x4 and a 2 lb hammer drive it home . Works everytime. I doubt there is anything wrong with your balancer ,just close tolerances .I wouldn't try using the bolt to pull it in you'll just turn the engine or strip / snap off the bolt