- Inspect the input housing and shaft assembly for the following conditions:
 
| •  | Spline wear - internal and external | 
 
| •  | Input speed sensor models, rotor teeth for cracks or damage | 
 
| •  | Three turbine shaft ball check valves are present and move freely | 
 
| •  | Retainer and ball check valve assembly (620) | 
 
| •  | Orificed cup plug (698) | 
 
- Test the input housing for cracks by tapping housing with wooden handle. Housing should produce a sharp ring.
 
- Inspect the turbine shaft oil seal ring (619) grooves for damage or burrs. The oil seal rings (619) must fit loose into the ring grooves.
 
- Inspect the oil feed passages for obstructions.
 
- Apply compressed air into the passages indicated.