TM 10-3930-659-34 5-8. TURBOCHARGER TEST AND REPAIR (Con’t). 10. Remove    four    screws    (19)    and    back     plate assembly (18) from center housing (5). 11. Remove   preformed   packing   (20)   from   center housing (5).  Discard preformed packing. 12. Remove  piston  ring  (21),  thrust  collar  (22),  and thrust bearing (23) from center housing (5). 13. Remove two outer retaining rings (24),  bearings (25),  and  inner  retaining  rings  (26)  from  center housing (5). c.           ASSEMBLY 1. Install two inner retaining rings (26), bearings (25), and outer retaining rings (24) in center housing (5). 2. Install thrust bearing (23) and thrust collar (22) in center housing (5) with piston ring (21). 3. Install new preformed packing (20) on center housing (5). 5-58