TM-9-2815-220-34 Direct Support Manual for AVDS-1790-2C and AVDS-1790-2D Engines Download

up all sludge or gum d�posits. 1 (2) Wash passages by flushing with dry-clean- 1 ing solvent (P-D-680, Type 11). Be sure passages are free from obstructions and remove any particles which might later become dislodged and contami- nate the oil system. (3) After cleaning, dry passages with compressed air. d. Electrical Cables and Flexible HoJes. Clean cables and flexible hoses with soap and water. NOTE Do not allow dry-cleaning solvent or mineral spirits paint thinner to be in prolonged contact with the rubber com- ponents and flexible hoses. These cleaners cause leather, rubber, and synthetic materials to dry, rot, and lose pliability, making them unserviceable. e. ll and Needle Bearing!. (1) Bearings require special attention in cleaning and oiling. After removing the: :,urface dirt, oil or grease, the bearings, except the sealed, permanently lubricated type, should be placed. in hot oil (about 1F.) to lꝏsen congealed oil and grease. After cleaning, the bearings should be wrapped tightly in oiled or waxed paper until inspection and assembly. NOTE  not immerse sealed type ball bearings in diy-cleaning solvent (P-0-680, Type II), or hot oil. Entrance of cleaning a- gent will destroy lubricants sea led in bearing at time of manufacture. Loss of lubrica11t will result in premature failure of bearing and possible severe damage to the engine. (2) Cl ean sealed ball bearings by wiping the exterior surfaces with a clean cloth moistened in ( dry- cl eaning solvent (P-D-680, Type II). Com- pressed air must never be used 1 cleaning or drying of ball or needle bearings. Damage to bearings will result from spinning of bearing by air blast. (3) Refer to TM 9-214 for information on in- spection, care, and maintenance of bearings. f. Painted Part.I. The reconditioning of painted parts should be a matter of gꝏd judgment. Parts that appear to be in gꝏd condition after cleaning, need not be stripped and repainted i n their entirety, but should be cleaned and designated for touch-up only. Parts that are rusted, or otherwise devoid of paint, must be stripped to bare metal. Rubber com- p o sition shroud seals must be removed and discarded before the parts can be stripped of paint. 3-37. Inspection a. General. The engines are precision built and the repair standards tables have been fixed at ex· TM 9-2815·220·34 tremely cle limits. The following general in· structions apply to all inspection predures. (1) Extreme care must be exercised in all phases of inspection. (2) Inspect finish of all parts. Mark all parts that require refinishing. b. Repair Standard!. Key letter� are used on the expled views to locate points of measurement for repair limits. Each table contains the maximum, minimum, and key clearances of new or repair parts. The clearances, listed mainly for reference, will automatically be achieved if the mating parts are within the dimensional tolerances listed in the tables. In some cases, a part that is out of dimensional tolerance may be used,· providing the mating part has been carefully selected and, when mated, is within the maximum clearance specified in the wear limits column of the tables. The wear limits indicate the point at which parts may be worn before replacement, in order to assure maximum service and minimum replacement. Normally, all parts which have not worn beyond dimensions shown in the "Wear Limits" column or are not damaged from corrosion, will be approved for service. c. Symbo. Symbols employed in the repair Stan- dards Tables are identified as follows: •-An asterisk in the "Wear Limits" column in- dicates that the part must be replaced when worn beyond the limits given in th� "Sizes and fits of new parts" column. L-The Jetter 11 L", following the tolerance dimen- sions given in the" Sizes and fits of new parts" column and the "Wear limits" column, in- dicates a lꝏse fit (clearance). T-The letter "T", following the tolerance dimen- sions given in the"Sizes and fits of new parts" column and the "Wear limits" column, in· dicates a tight fit (interference). d. CtingJ. (1) Inspect all ferrous (cast iron, steel, etc.) castings for cracks. Inspect all nonferrous (aluminum) castings for cracks. Suspected cracks in the nonferrous casting can be checked with a magnifyi ng glass (five power magnification minimum) and a strong light. Check particularly the areas adjacent to studs, pipe plugs, or threaded inserts and in sharp corners and fillets. (2) Inspect machined surfaces of castings for nicks, burs, or raised metal. Mark damaged ar�as for repair. (3) Check all mating flanges and mounting pads with a straight edge or surface plate for warpage. In- spect mating flanges and mounting pads for discoloration which may indicate persistant oil leakage. Change 3 3-59