dairyman
Guest
I took all the blades from our fan and weighed them on a kitchen scale. I wrote the weight on each blade in black marker.  Then I sorted the blades by weight and put matching weights directly opposite of each other.  It has been running that way with no noticeable trouble for about 8 years.  The sprocket is loctited to shaft.  Heat it a little and use two pipewrenches to remove.  I think it is just RH threadIJ  Fan drives clean grain and tailings and slack side is bottom of chain, so for sprocket to be self-tightening it has to be RH threadIJ