Locke Well & Pump Company

I have a Stenner chemical feed pump which is not pumping. I have taken it apart and noticed that the motor is moving the shaft, but when I put it back together the Roller assembly doesn't turn. I also noticed that when I put the roller assembly back on there is some play when I turn it. Could the roller assembly be slipping or could the motor be failing?

Did you check the phelonic gear ? ( its the fiber gear in the gear case ) The roller assembly is fitted to the shaft on a flat , has the inside of the roller assembly rounded out ?