TM-9-2520-254-34 Direct Support for M113 TX100-1 Transmission 2520-00-066-4240 Download

CHAPTER 5 REPAIR AND OVERHAUL (REBUILD) Section I. PRELIMINARY INSTRUCTIONS FOR TRANSMISSION OVERHAUL (REBUILD) 5-1. General a. Equipment Needed. Proper equipment must be available before disassembly is started. This equipment includes a suitable hoist of at least 1 / 2 ton capacity. proper hand tools and special tools, improvised tools. receptacles for small parts, wood blocks. wiping cloths, and an arbor press. Refer to paragraphs 3-4 and 3-5 for lists of special and improvised tools. b. Parts to Discard. Cotter pins, lock wires, lock strips, and gaskets should be discarded at trans- mission disassembly. New parts should always be supplied in such cases. c. Avoiding Component Damage. Care must be used to avoid damage to transmission components during disassembly, cleaning, inspection, repair, and reassembly. Scratches. nicks, and dents caused by careless handling may cause oil leakage or improper functioning and could result in trans- mission failure. All defective parts must be replaced. d. Torque Requirements. All standard torquing requirements for bolts, screws, and nuts are tabulated in table 6-1. Where special torque requirements apply. they will be found in the applicable text. 5-2. Cleaning Recommendations a. Importance of Cleanliness. Cleanliness is of paramount importance in servicing the trans- mission. All components must be thoroughly cleaned and kept clean throughout the rebuild process. The presence of dirt can cause malfunction and possible failure of the transmission. Refer to TM 9-208-1 and TM 9-208-2. WARNING Forewarn personnel in the immediate area when using compressed air for cleaning. Compressed air. coming into contact with the human skin or causing flying metal chips. can cause serious injury. b. Cleaning Parts. (1) Every component should be thoroughly cleaned after the transmission is disassembled. Cleaning is necessary to insure effective inspection for wear, damage, and serviceability of com- ponents. (2) The utmost care should be used in han- dling of parts during cleaning and overhaul (rebuild ) operation. Nicks, scratches, dents, or burs can prevent proper assembly or cause malfunction after assembly. This is especially true of valves and valve body parts. (3) Abrasives, files, scrapers, wire brushes, and sharp tools should never be used on surfaces where finish is important to the operation or sealing of parts, except where specifically recommended. (4) Gum or varnish may be removed by soaking in dry cleaning solvent or mineral spirits paint thinner and by the use of a soft bristle brush. Crocus cloth may be used to remove minor surface irregularities. Lapping compound may be used, if required, in valve body bores to prevent valves from sticking. Clean thoroughly to remove compound after use. (5) A soft wire (brass or copper) may be used to clean oil passages. Always flush such passages thoroughly after cleaning. (6) If steam cleaning is used, dry the cleaned parts immediately with compressed air, and apply a film of oil to prevent rusting. Never use lye or caustics which will corrode or etch metal surfaces. (7) Do not clean the lubricant from new bearings. Keep new bearings wrapped until they are to be installed. Soak bearings which have been in service in dry cleaning solvent or mineral spirits paint thinner to loosen deposits of dirt. Do not spin bearings during cleaning or drying. After cleaning, turn bearings by hand and note any evidence of grit. Reclean them if grit is present. Refer to TM 9- 214 for further information on cleaning bearings. 5-3. Inspection and Repair Recommendations a. Castings. Forgings. and Machined Surfaces. (1) Inspect all castings and forgings for breaks, cracks, and wear or scoring that would impair serviceability. Remove nicks and small surface irregularities with crocus cloth or a soft stone. (2) Inspect all oil passages for obstructions and dirt. Reclean passages if necessary. (3) Inspect mounting faces for nicks, scratch- es, and scores. Remove minor defects with crocus cloth or a soft honing stone. Replace any parts in 5-1