TM9-2815-202-34 (27)  Adjust  bridges  as  follows: CAUTION Do not loosen or tighten locknut with bridge installed in cylinder head. Bent bridge guide or rear valve stem may  result. (a) (b) (c) (d) (e) (f) Place valve bridge (17) in a vise or bridge holding fixture and loosen locknut (103)on bridge adjusting   screw   (104). Install valve bridge (17) on valve bridge guide (18). While  firmly  pressing  straight down  on  pallet  surface  of  valve bridge  (17),  turn  adjusting  screw (104)  clockwise  until  it  just touches valve stem. Then turn screw an additional 1/8 to 1/4 turn and  tighten  locknut  (103)  finger tight. Remove  valve  bridge  (17)  and place in a vise or holding fixture. Hold  adjustment  screw  (104)  from turning  with  screwdriver  and torque  locknut  (103)  on adjustment  screw  to  20-25  Ib-ft (27-34  N-m). Lubricate valve bridge (17) and valve bridge guide (18) with engine oil and install bridge in original   position. Place  0.0015  inch  feeler  gage under  each  end  of  valve  bridge (17).  When  pressing  down  on pallet  surface  of  valve  bridge, both gages must be tight. If both feeler gages are not tight, readjust  screw  as  outlined  in steps (a) thru (e). 4-211