Using a wrench, rotate the shaft, feeling, notably during the initial rotation, but then disappeared. Open the lid to check bearing it is in normal condition and add grease and assemble the back filled commissioning normal.
Use a wrench to rotate the shaft was rotated stumble at the start, but then disappeared. Thus opening the door to check it, bearing in normal condition. And fill up grease and reassembly. Trial run normally
Use the wrench shaft feel stumble at the start rotating but then disappeared. And then open the ball bearings to check it out in normal conditions. And fill the grease add and assemble back experiment operate normally.