Locknut worn out. replace locknut, Rough gears. run in or change gears, Worn bearing. replace bearing – Servis-Rhino RHINO EC72 User Manual

Page 128: Bent shaft. replace oil seal and shaft, Oil seal race rough. replace shaft or repair race, Oil seal installed wrong. replace seal, Of seal, Oil level too high. drain oil to proper level, Gasket damaged. replace gasket, Bolts loose. tighten bolts