wipers are driving me crazy!

Ok so I have been running with one wiper for a while because I can't keep the second on the ball....... I replaced all the bushings after I got the car as the arms fell off when I turned on the wipers.... I have no idea why the cross bar keeps coming off. It seems like it just pops off after about one motor rotation. The bushings I got were from autozone help section multi pack...

I dunno what else to do.........