TM 10-3930-669-20 2-16.  DRIVE AXLE SYSTEM TROUBLESHOOTING (CONT). 3.  DRIVE AXLE ENGAGING HARSHLY WHEN SWITCHING DIRECTION. INITIAL SETUP Tools and Special Tools Tools and Special Tools Tool Kit, General Mechanic's: Automotive (Item 1, Appendix B) References TM 10-3930-669-10 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 Planetary or wheel(s) loose or damaged. If wheels or planetaries are loose or   damaged,   axle   will   engage harshly. ¬ 2-384