Little more information required.
a) is there a gearbox involved or are you looking directly at stepper shaft
b) how must does it move by (part of 1 step or 1 complete step)
c) do you keep the coils energised when stopped
d) if answer to (c) is "yes" are the coils really energised
e) if the answer to (c) is "no" is there a possibility of at least one of the coils being energised
f) how many coils are used
g) and finally the model number of the stepper motor