We have a cub GT 3200 lawn tractor with a 60" #291 mower deck. Here is the problem. I have trouble breaking the mower spindle nuts loose when it is time to sharpen the blades. The nuts are tightened by using a half inch breaker bar and socket. So there isn't a lot of tourque put on the nuts like would result when a impack wrench is used. The blades are sharpened once a month during the mowing season. It seems that they get tighter with use. Are any of you having this problem and any ideas on how to fix the problem?