TM-9-2520-234-35 Technical Manual for M109 Transmission XTG-411-2A Download

CHAP 5, SEC I PRELIMINARY INSTRUCTIONS FOR PAR 72 POWER TRAIN OVERHAUL tightness of fit in the bore. If defects are found, replace the bearing using the proper replacer. Note. Do not remove needle bear- ings unless replacement is neces- sary, since removal usually results in destruction of the bearing. d. Bushings, Bushing-type Bearings - and Thrust Washers (1) Inspect bushings and bushing- type bearings for size, scoring and out-of- roundness, burrs, sharp edges and evidence of seizing. Minor scores, sharp edges and scratches may be removed with crocus cloth. Out-of-round, deeply scored or worn parts should be discarded. Note. Do not remove bushings bushing-type bearings unless replacement is necessary, as re- moval usually damages these parts. (2) Remove bushings and bushing- type bearings by using a puller or press when possible. Bushings in blind holes may require removal by sawing or the use of a narrow cape chisel. Caution. If necessary to cut out a bushing, do not damage the bore into which it fits. (3) Inspect thrust washers for wear, distortion, scores and burrs. Cor- rect minor defects but replace parts that are worn, scored or deformed. e. Oil Seals, Preformed Packings and Gaskets (1) Inspect hook-type seal rings for wear, distortion and broken hooks. Replace defective seal rings. Install a new hook-type seal ring if the ring shows any wear on the outside circumference, or if there is excessive side wear. The sides of the seal ring must be smooth within 0.005-inch maximum side wear. The sides of the shaft groove (or the bore) into which the seal ring fits should be smooth within 50 microinches equivalent and square with the axis of rotation within 0.002-inch. If the sides of the grooves have to be reworked, install a new seal ring. (2) Inspect metal-encased lip- type seals for cracks, wear, cuts and brit- tleness. Inspect springs and seal shells. Replace any seals found defective. Note. Any time a metal-encased lip-type seal is removed, it must be replaced with a new seal. f. Gears (1) Inspect gears for burrs, wear, pitting and broken teeth at tooth contact areas. (2) Inspect bores of planetary pinions for wear and pitting of bearing contact areas. (3) Remove burrs using a soft honing stone. Replace gears that are excessively worn or pitted. g. Splined Parts (1) Inspect splined parts for twisted or broken splines, burrs and ex- cessive wear. (2) Remove burrs using a soft honing stone. Replace parts which have twisted or broken splines and excessive wear. h. Clutch Plates (1) Inspect friction-faced steel plates for burrs, embedded metal par- ticles, severely pitted faces, excessive wear, cracks, distortion and damaged splined teeth. Remove burrs using a soft honing stone. Replace plates which have other defects. (2) Inspect steel plates for burrs, scoring, excessive wear, distortion, em- bedded metal, galling, cracks, breaks and damaged spline teeth. Remove burrs and minor surface irregularities using a soft honing stone. Replace plates which have other defects. 76 Change 2