Hello,
I have a problem with an Ur5 CB3, the robot had only been used for demonstrations, it has not been used for some time because it has another robot. Recently I went to do some tests with the UR5 and I realize that the robot behaves as if it had a load. The wrist 3, when I turn it with the free drive, does not stop. What could I do to solve this problem?
Thank you
Does it make noises when you turn it?
Could be an old TCP and payload which have not been removed. 
Go to Installation and remove or set TCP correct as well as Payload, if you have not done this.
Also, an update will never harm anything if it’s running an old software version.