TM    10-3930-638-24&P 3-24. STEERING SYSTEM MAINTENANCE (cont) b. Steering Gear (cont). 20 STEP LOCATION ITEM ACTION REMARKS INSPECTION  (cont) NOTE (cont) Spool (30) is not serviced separately. Replace steering gear assem- bly if spool is defective. 21 spool  (30) Inspect Replace steering gear assembly if splines chipped or broken, or if outside diameter or control edges scored, worn or damaged 22 End cover (3) Inspect Replace if pin damaged, or if lapped face nicked, burred, or scored 23 Upper cover (14) Inspect Replace if cracked or broken, or if end nicked or burred 24 Drive ring (31) Inspect Replace  if  splines  chipped  or  damaged NOTE Housing  (43)  is  not  serviced  separately.  Replace  steering  gear  as- sembly if housing is defective. 25 Housing (43) Inspect Replace steering gear assembly if threads damaged, or if bore or ends nicked, burred or scored NOTE Replace commutator (7) and commutator ring (8) as a matched set. Commutator and ring are not serviced separately. 26 Commutator (7) and Inspect Measure  side  clearance  between  commuta- commutator ring (8) tor and ring. Replace commutator and ring if either is scored, pitted or burred, or if side clearance is more than 0.0015 inch 27 Replace if nicked, burred or scored Inspect Manifold (9) and spacer (12) 3-169