bill_stauty You won't damage anything if the other blades are still intact. However, if one blade broke off, then chances and you did not bump into or mess with it, chances are the plastic is brittle and others will follow. As far as changing it, you can unbolt the drive shaft from the back rag joint disc (2 bolts) and you should be able to slide it out. You may need to unbolt the engine (4 bolts from the underside of the tractor, just rock the front axle to get to 2 of the bolts and the other two are further back and easy to get to) if you need to unbolt the engine. Remove the drive shaft, knock out the roll pin on the front of the drive shaft (this may be the toughest part of the repair). Remove fan clip, slide old fan off after
noting its placement on the drive shaft and the direction of the fan blades on the old fan. Put new fan on
in same location on drive shaft and with the blades of the fan in the same direction as the old fan. Replace clip to hold fan in place, replace pin in drive shaft, bolt things back up and you are back in action.
Cub Cadet 123