TM 10-3930-659-20 16-7. REAR WINDOW WIPER ARM AND BLADE MAINTENANCE. This Task Covers: a.  Wiper Arm Blade Replacement c. Installation b.  Removal Initial Setup: Materials/Parts: Tools/Test Equipment: • One gasket • General mechanic's tool kit (Item 44, Appendix F) • One locknut • Three lockwashers a. WIPER ARM BLADE REPLACEMENT 1. Remove  locknut  (2),  nozzle  (3),  and  wiper  arm blade  (1)  from  window  wiper  arm  (4).    Discard locknut. 2. Install wiper arm blade (1) on window wiper arm (4) with nozzle (3) and new locknut (2). TA706984 16-22