I just received the hub seal replacement kit from AppliancePartsPros and it all is complete except that I can't get the new aluminum hub assembly all the way onto the transmission shaft. I have thoroughly cleaned the spines on the shaft and the new part easily slides onto the shaft initially but will not go all the way on (ie not far enough to be able to get the nut on the shaft). It appears that the hub assembly may not have been milled out completely on the bottom side. Any suggestions?

I've looked at it in quite a bit of detail and it looks identical to the old part. It binds up with about a inch to go before being seated on the shaft. I've tried lightly tapping it and i continues to bind up.