TM 1-1520-238-23
Change 9
6-503
6.121.
INTERMEDIATE GEARBOX INSPECTION – continued
NOTE
If cracks in the intermediate gearbox flange and/or the shouldered shaft are suspected,
refer to TM 1-1520-264-23.
(3) Check identification marking. Must be readable.
(4) Check coupling mounting diameter. Minimum diameter 2.1221 INCH. Use caliper set.
(5) Check diameter of pilot between shaft flange and gear. Minimum diameter 2.4995 INCH. Use caliper set.
(6) Check diameter of pilot between gear and plug end of shaft. Minimum diameter 2.0940 INCH. Use caliper
set.
(7) Check spline teeth.
(a) No scuffing, scoring, or spalling allowed.
(b) Maximum pitting depth before blending 0.008 INCH. Use depth gage.
(c) Maximum wear step 0.008 INCH. Use depth gage.
(d) Measure “Over Balls” diameter with two 0.2500 INCH diameter gage balls placed in tooth spaces
approximately 180 degrees apart. Take three “Over Balls” measurements at locations approximately
120 degrees apart. Minimum “Over Balls” diameter 2.737 INCH. Use caliper set.
(8) Check five 0.2500 INCH hole diameters. Maximum diameter 0.2585 INCH. Use caliper set.
(9) Check plug for looseness and insertion depth. Minimum insertion depth from end of shaft, 0.060 INCH. Use
depth gage.
(10) Check cadmium plating. Damaged and missing cadmium plating is acceptable.
h. Check breather lubricant buildup.
i. During operation, some gearboxes may expel small amounts of grease from the gearbox breather vent. If
lubricant is evident; remove, clean, and reinstall breather (para 6.126).
(1) No additional reservicing of the gearbox need be performed.
j. Check diffuser for serviceability.
(1) Check for fractures and/or cracks. None allowed. Use fluorescent inspection kit (TM 55-1500-335-23).
(2) Check for nicks, burrs, gouges, and corrosion, not deeper than 0.020 INCH before blending, and not over
25 percent of area. Not more than 10 percent damage in one localized area. Use depth gage.
END OF TASK
