Inline 6 Harmonic Balancer Istall?

[Hair]

71 Inline 250 6 cylinder: I pulled the harmonic balancer off with a puller and I noticed that it did not have a bolt holding it on, but at that time I didn't think much about it. Now, I'm putting it back on and I was going to pull it on with the bolt and I realized that there is no bolt or bolt hole in the crank. Evidently the balancer just sticks on there with no bolts??!! Here's my problem though, I've been trying to drive it back on with a big rubber mallet, and man, that thing is a monster to drive on. How am I supposed to get it on there with no bolt to pull it on there with? Am I just supposed to keep beating the snot out of it until its on? It seams like it has stopped moving now, but I still have a half inch or so to go. What am I doing wrong? I don't normally beat the harmonic balancer on, but I don't see any other way. I'm hitting it good and square in the center to avoid tearing it up. But is this the right way?? By the way, it's the same crank and balancer that I took apart so I know it's not a parts problem.