UM2+. 7-8 year old - stepper motor hard to turn/grinds

[Neillc 0]

hello, 

 

We have an early UM2+. (7-8 years?)  that makes a horrendous noise on one axis on and off when moving the print head.

 

we  checked the belts and they are being shredded by the stepper motor.  (black bits  all at the back).

 

We have removed the stepper motor and the shaft is hard to turn by hand and then locks up at the end of a rotation.

 

Am I right in thinking the stepper motor should rotate freely  with a little resistance against the magnets  and should not lock up  or be hard to turn by hand?

Edited September 10 by Neillc