Installing new Front PTO Shaft and Pulley

[Chuck G]

I'm trying to install a new front PTO shaft on my 2000 Simplicity Legacy tractor. Last summer I installed the "update kit", for the front PTO shaft because the bearing flanges broke. Again this summer the bearing flanges broke and my service/parts store advised me that they had been having some problems with the update kit's axle insert being too long and not allowing the bearing in the flange to spin freely. This time I filed down the insert, replaced the bearing flanges again and inserted the PTO shaft. This brings me to my question, after unsuccessfully trying for a couple of hours to reinstall the front pulley with the key onto the PTO shaft I have given up. What's the trick? Each time I attempt to put any pressure on the pulley to slide it further onto the shaft and over the key the shaft back into the axel towards the rear of the tractor. I can't install the pulley on the shaft and then insert the shaft because the rear of the shaft is larger then the front and the rear is too large to fit throught the axel. I'm guessing there is some way/"trick" in keeping the shaft in place, but I don't know it. Any help or suggestion would be great.