Mowing 955 belly mower blades come off

[Bjohn]

I just stripped sandblasted and painted a belly mower for a 955. I put it back together but the blades are spinning off when I turn the power takeoff off. Does anyone have any suggestions? I tried not putting the protective metal cup back on thinking that was keeping the blade from seating properly and they still came off. I'm thinking about some lock washers. I know the blades need to seat with the center coming through the blade and I used a breaker bar with 1/2 inch sockets to tighten. I'll try some lubriant to see if they seat better but I'm unsure what else to try. Any suggestions would be appreciated.

 

[beenthere]

Do you have the concave washer under the stud that contacts the blade turned the correct way? I think that is the system you have, similar to my Xseries decks. Maybe not.

These washers may look flat, but they are not. The outer rim is to contact the blade, with the head of the stud pushing the center of the washer to hold it on tight.

Otherwise, new studs and washers might be in order.