n1. AXLE DIFFERENTIAL(S) NOISY (CONT)            TEST OPTIONS                        KNOWN INFO              YES Are the axle differentials free from damage? NO TM 9-2320-365-20-2 2-1898          Change 1 Visual inspection     REASON FOR QUESTION     Axle differential(s) may be unusually noisy when operating if damaged.            TEST OPTIONS                        KNOWN INFO              Is the axle differential oil at proper level and free of contamination? NO YES Visual inspection     REASON FOR QUESTION     Low oil level will cause axle differential(s) to make unusual noises and lead to damage. Add/change oil (Appendix H). 3. 4.        POSSIBLE PROBLEMS        Damaged axle differential. Low or contaminated oil in axle differential. Faulty pinion drive yoke.        POSSIBLE PROBLEMS        Low or contaminated oil in axle differential. Faulty pinion drive yoke. No visible leaks of planetary wheel ends or wheel bearings. No visible leaks of axle differential or pinion drive yoke. No visible leaks of planetary wheel ends or wheel bearings. No visible leaks of axle differential or pinion drive yoke. Axle differential(s) free from damage. Perform Propeller Shaft Troubleshooting (g1. Drive Shaft or Universal Joint Unusually Noisy When Operating