2-11. Repair

TM 9-2815-237-34 · Chapter 2 — Engine Maintenance

a. General Instructions. Repair of most parts and components is limited to general procedures outlined in applicable maintenance instructions and the following detailed procedures “b” through “h”.

Repaired items must be thoroughly cleaned to remove metal chips and abrasives to prevent them from entering working parts of the engine.

b. Castings. (1) All cracked castings will be replaced. (2) Only minor repairs to machined surfaces, flanges, and gasket mating surfaces are permitted. Remove minor nicks, burrs, and/or scratches with: (a) Fine mill file. (b) Abrasive crocus cloth dipped in cleaning solvent. (c) Lapping across a surface plate. (d) Remachining of machined surfaces to repair damage, warpage, or uneven surfaces is not permitted. Replace castings. (3) Repair damaged threaded pipe plug and/or capscrew holes with a thread tap or repair oversize holes with threaded inserts.

c. Bearings. See TM 9-214.

d. Studs. Replace all bent and stretched studs. Repair minor thread damage with a thread restorer file. Replace studs having stripped or damaged threads as outlined below: (1) Remove, using a stud remover. Back studs out slowly to avoid heat buildup and seizure which can cause stud to break off. (2) If studs break off too short to use with a stud remover, use extractor to remove. (3) Replacement studs have a special coating and must have a small amount of antiseize compound (Appendix B, Item 3) applied on threads before stud is installed. Install replacement stud slowly to prevent heat buildup and snapping off.

e. Gears. (1) Remove gears using pullers, as required. (2) Use the same methods described in paragraph 2-11.b.(2) for castings t O remove minor nicks, burrs, or scratches on gear teeth. (3) If keyways are worn or enlarged, replace gear.

f. Bushings and BushingType Bearings. When bushings and bushing-type bearings seize to a shaft and spin in the bore, the associated part must also be inspected and replaced, as required.

g. Oil Seals. (1) Remove oil seals, being careful not to damage casting or adapter bore. (2) Always install new seal in bore using proper seal replacing tool.

h. Cylinder Block or Cylinder Head. Repair of cylinder block and cylinder head is limited to procedures outlined in paragraphs 2-16 and 2-21. Cylinder block or cylinder head must be replaced if measurements are outside tolerance limits listed in table 2-2 or table 2-3.