TM-9-2815-202-34 Technical Manual for 8V71T Engines for M109 Howitzer Download
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TM9-2815-202-34 CAUTION Do not use crocus cloth on bushing side of pin. Bushing side requires a polished finish. (4) Use crocus cloth wet with fuel oil to remove any trace of fretting and/or corrosion on connecting rod saddle to piston pin contact surface. d. Inspection (1) Dome and Skirt NOTE Indications of overheating or burned spots may be result of an obstruction in connecting rod oil passage. (a) (b) (c) Examine piston skirt and dome for score marks, cracks, damaged ring groove lands, loss of tin plating, or indications of overheating. Replace any piston severely scored or overheated. Check tapered fire ring groove width with piston groove gage (18). Slide NO-GO wire (0.106 inch diameter) of tool completely around fire ring groove. Replace dome if wire is below flush at any one area. The GO wire (0.100 inch diameter) should be flush or protrude slightly from fire ring groove. Check cylinder liner and block bore for excessive out of round, taper, or high spots which could cause failure of piston (see Para 4-34). (2) Piston Pin CAUTION When using a piston pin, do not refinish highly polished and lapped surface of pin in any way. NOTE New piston pin has diameter of 1.4996 to 1.5000 inches. Replace piston pin if worn to diameter of 1.4980 inches or less. Inspect piston pin for signs of fretting. 4-135