Need wiper help

During the last snow, I left my wipers on. When I started the car the next morning, the wipers stopped working. The motor still works. It just disconnected at the joint between the motor and the wipers. I have popped it together several times. Sometimes it will work for a while and sometimes it disconnects right away. Is there a part or grease that holds them together? I see no damage to the joint. Please Help!