Jeep Engines - Oljeep

360 AMC V-E) (PISTON AND CONNECTING ROD ASSEMBLY) 3896. The rod bolt head should be seated against the flat,machined surface in the rod.7.8.9.For a race engine, the big end rod should be sized tothe minimum diameter to get the maximum crush fromthe bearing.Shot-peening the rods is recommended if they haven'tbeen already.Clean all parts before proceeding.Inspectiona. Connecting Rod BearingsIClean the inserts.Inspect the linings and backs of the inserts for anirregular wear pattern. Note any scraping, stress cracksor distortion. If the bearing has spun in the rod, replacethe bearing and connecting rod and inspect thecrankshaft journal for scoring.The wear pattern is always greater on the upper bearinginsert. Grooves can be caused by the rod boltsscratching the journal during installation.Inspect for material imbedded in the linings that mayindicate abnormal piston, timing gear, distributor gearor oil pump gear wear (Figure 7-13).Inspect the fit of the insert locking tab in the rod cap.If the inspection indicates that the insert tab may havebeen pinched between the rod and rod cap, replace theupper and lower bearing inserts.Inspect the contact area of the locking tab. Abnormal wearindicates bent tabs or improper installation of the inserts.Replace bearing inserts that are damaged or worn.b. Connecting RodsMisaligned or bent connecting rods can causeabnormal wear on pistons, piston rings, cylinder walls,connecting rod bearings and crankshaft connecting rodjournals. If wear patterns or damage to any of thesecomponents indicates the probability of a misalignedconnecting rod, inspect it for correct rod alignment.Replace misaligned, bent or twisted connecting rods.Connecting Rod Bearing FittingConnecting rod bearing inserts are selectively fit to theirrespective journals to obtain the desired operatingclearance. In production, the select fit is obtained by usingvarious sized, color coded bearing inserts. The bearingcolor code appears on the edge of the insert.Note: Bearing size is not stamped on production inserts.The rod journal size is identified in production by a colorcoded paint mark on the adjacent cheek or counterweighttoward the flanged (rear) end of the crankshaft. Refer tothe color codes listed on the Connecting Rod BearingFitting Chart (in your service manual) to identify thejournal size and select the correct bearing inserts to obtainthe correct clearances.Caution: Never use a pair of bearing inserts that aregreater than 0.025 mm (0.001") difference in size.When required, different sized upper and lower bearinginserts may be used as a pair. A standard size insert issometimes used in combination with a 0.025 mm (0.001")undersize insert to reduce clearance by 0.013 mm(o.ooost~).Service replacement bearing inserts are available in pairs inthe following sizes:Standard0.025 mm (0.001") undersize0 0.051 mm (0.002") undersize0.254 mm (0.010") undersizeThe size is stamped on the back of the service replacementinserts. The 0.051 mm (0.0021') undersize inserts were notused for production engine assembly.Measuring Bearing-to-Journal ClearanceJ8909-381. Plastigauge Methoda. Wipe the bearing inserts and rod journal clean.b. Lubricate the upper insert and install it in the rod.c. Place a strip of Plastigauge across the full width ofthe lower insert at the center of the bearing cap.The lower insert must be dry.Figure 7 - 13-.T - 1 1