Hello, and thanks for taking a moment to read this post... I have a Kubota B7500 that has a Curtis Cab. Yesterday, the wiper arm complete with its blade came off when I was using it. It appears to be held onto the spindle through a series of interlocking grooves and then tightened with opposing Allen head set screws. I reinstalled it and tightened the set screws but it came off again.... any suggestions? Thanks