NMWR-9-2815-220 Overhaul Manual for M60 M88 Engine AVDS-1790-2CA, AVDS-1790-2DA, AVDS-1790-2DR Download
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0016 00-4 Change 1 NMWR 9-2815-220 CAMSHAFT AND DRIVE ASSEMBLIES OVERHAUL—Continued 0016 00 RECLAMATION – Continued (3) Prepare I.D. surface in accordance with standard metalizing procedures as follows: a Mask areas, not to be coated, with suitable grit blast masking material. b Grit blast bearing bore with clean, oil free G25 chilled iron grit. c Rough thread the I.D. surface. (4) Remove grit blast masking material and remask with suitable metalspray masking material. (5) Using Metco 10E or 12E Wire Spray System, apply a bond coat of Metco 405 nickel aluminide to the prepared surface. (6) Apply top coat of Metco Spraysteel LS to obtain a 0.0300 in. (0.7620 mm) undersize bore dimension. (7) After the plate has cooled naturally to room temperature, remove masking and machine bearing bore to drawing specifications. NOTE All mounting surfaces repaired by this process shall be 100% inspected for coating integrity after machining. The coating shall show no bond separation at the coating to base metal interface. The coating shall be free from blistering, cracking, chipping, and frayed edges. There shall be no bleedout of oil or other contaminants through the finished coating. (b) The camshaft gear housing (part no. 11682703 and 11682701). Reclaim 2.5000 in. (63.5000 mm) cam bore bearing surface by metalspray. Refer to Table 11 for size reference. NOTE To demonstrate proficiency and attain certified status, an operator shall flame spray a test piece in accordance with this specification which shall be destructively and metallographically examined to assure bond integrity and coating soundness. To maintain certified status, an operator must consistently produce acceptable repairs relative to the flame sprayed coating and pass a yearly destructive examination for bond and coating integrity. (1) Thoroughly clean and degrease housing using cleaning compound degreaser.