TM 10-3930-669-20 2-16.  DRIVE AXLE SYSTEM TROUBLESHOOTING (CONT). 2.  DRIVE AXLE NOISE GREATER UNDER POWER THAN DURING COAST. INITIAL SETUP Tools and Special Tools Tool Kit, General Mechanic's: Automotive (Item 1, Appendix B) References TM 10-3930-669-10 LO 10-3930-669-12 Equipment Condition Engine OFF (TM 10-3930-669-10) MAIN POWER switch OFF (TM 10-3930-669-10) Parking brake applied (TM 10-3930-669-10) Wheels chocked (TM 10-3930-669-10) KNOWN INFO TEST OPTIONS Nothing. Visual inspection. POSSIBLE PROBLEMS REASON FOR QUESTION Drive axle oil incorrect. Drive axle oil level low. If drive axle oil is incorrect, gear friction   will   increase   and   make more noise under power. ¬ 2-380