[chengny]

Was that particular balancer previously mounted on that crank snout? If it was, try this method:

Put the balancer in the oven at the lowest setting (usually about 175 F). Let it stay in there for an hour or so.

While the balancer is warming up, chill the crank snout. Crush some ice in a plastic bag and wrap the bag on the snout. Before you place the bag on the snout, apply a thin coat of never-seize to the OD and the key.

After the balancer has warmed up (and the snout has been chilled), take it from the oven and quickly bring it to the engine.

Remove the ice bag and set the hub on the end of the crankshaft. Using a hammer and a block of wood - with the end grain of the wood against the balancer hub - try to tap the balancer onto the shaft. Tap is the key word - don't go all Hercules on it's ass. Slamming the balancer on with a BFH can cause internal engine damage (e.g. to the face of the thrust bearing)

If the hub now is able to be tapped past the point where you were getting jammed up before, you can either:

1. continue to tap it till it's home

2. Or if tapping won't get it all the way on, switch to one of the tools mentioned above - or the homemade rig suggested by Curtis (AKA enaberif, AKA firebane).

The thing is, you have to have one of these tools right there and ready to use. If you don't have them in hand, the clearance you gained by heating the balancer/chilling the shaft will quickly be lost. You'll have to pull the balancer and start all over again.