TM 10-3930-659-34 5-8. TURBOCHARGER TEST AND REPAIR (Con’t). 4. Install    back    plate    assembly    (18)    on    center housing (5) with four screws (19). 5. Install wheel shroud (16) and piston ring (17) on wheel and shaft assembly (3). CAUTION Use  care  when  installing  wheel  and shaft assembly in center housing not to damage bearings installed in center housing.  Improper installation can   damage   turbocharger   assembly or bearings. 6. Install  wheel  and  shaft  assembly  (3)  on  center housing (5) and thrust bearing (15). 7. Clamp turbocharger turbine wheel holding fixture (12) in vise.  Install center housing (5) and wheel and shaft assembly (3) in holding fixture. 8. Install impeller (13) on wheel and shaft assembly (3) with new locknut (14). 9. Remove  center  housing  (5)   from   turbocharger turbine wheel holding fixture (12). 5-59