TM 1-1520-238-23
6-99
6.17.
ENGINE NOSE GEARBOX INSPECTION – continued
(5) Check for pulled or missing studs. None allowed.
(6) Check threaded inserts for looseness. None allowed.
(7) Check packing groove in filter bowl area for nicks, gouges, or burrs.
(a) Repair damaged areas 0.004 INCH or less deep by blending. Use depth gage.
m. Check gearbox mounting flanges for damage.
(1) Maximum dent depth, 0.060 INCH. Use depth gage.
(2) Scratches, nicks, gouges, and pits must be blended out (minimum blending radius of 0.400 INCH), using
largest blend radius practical.
(a) After blending, repaired surfaces must be inspected with a 10X lens to ensure that no cracks have
been started in base material.
n. Check quill shaft for serviceability.
(1) Check for corrosion, scratches, nicks, gouges, and burrs.
(a) Damage not to exceed 0.020 INCH. Repair by blending. Use depth gage.
(2) Check for damage in packing grooves (four places). None allowed.
(3) Measure spline teeth wear by traversing a dial indicator over wear step. Use depth gage.
(a) Acceptable wear step is 0.030 INCH maximum.
(b) Check surface radii for damage. None allowed.
o. Check output shaft for serviceability.
(1) Check crossed, flattened, or stripped threads. None allowed.
(2) Check for external spline wear.
(a) Measure spline teeth wear by traversing a dial indicator over wear step. Use depth gage.
(b) Acceptable wear step is 0.030 INCH maximum.
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