TM 10-3930-669-34 13-3.  CARRIAGE REPLACEMENT/REPAIR (CONT). d. Assembly. (1) Install  anchor  (4)  on  carriage  (5)  with  two  lock nuts (17). (2) Install  four  roller  bearings  (15)  on  carriage  (5) with shims (16), washers (14), and screws (13). WARNING Use care when removing or installing snap   and   retaining   ring.      Snap   and retaining rings are under spring tension   and   can   act   as   projectiles when released and could cause severe eye injury, (3) Install four rollers (10) on carriage (5) with shafts (12),  shims  (11),  shims  (9),  retaining  rings  (8), and lock screws (7). 13-30