TM9-2815-226-34-1 - JATONKAM35s HOME ON THE WEB

TM 9-2815-226-34-1g. Main bearing line boring.NOTEReplacement main bearing caps are not machine finished. They are furnished with0.015 in. (0.381 mm) excess material in bore. They must be machined to theirrespective bearing saddles to ensure proper bearing shell fit. Line boring is alsorequired if bearing saddle is damaged, misalined, excessively tapered, or exceedsmaximum diameter. Rebored saddles are then fit with salvage sleeves. Sleevesare then bored to accept standard bearing shells.(1) Install boring bar.(a)(b)Remove two main bearing caps which do not require boring. Select two caps which are at each endof cylinder block or as far apart as possible.If two caps cannot be selected which are far apart from each other, bridges must be installed toprovide boring bar with required support and stability (para 3-9i).(c)Install ST-1177-39 centering rings in center of bearing saddles. Tap in position with soft headhammer.NOTECaps fit tightly to provide proper seating.(d)(e)(f)(g)Assemble two main bearing caps with centering rings in saddles and torque capscrews as specifiedin para 3-94e.Assemble new caps as required and torque to specifications.Lubricate centering rings and boring bar with engine oil.Slide boring bar through centering rings in block.3-91