WI Bowhunter wrote:
Well, I took the cover off inside and the 4 bolts were pretty loose. I used. A hand driven nut driver and tightened them quite a bit. I did not over torque them i hope. I did nut turn them in as far as I could, but decently snug. This did not solve the problem completely. I'll check the topside tomorrow in the daylight. I think tightening it helped control the shaking, but it seems the fan is not valanced
A little Loctite® on the bolts will prevent them from loosening.
The fan may be just dirty and cleaning it will correct the imbalance.