GM 12564669
Piston

You should start connecting rod servicing by unmounting cylinder heads while hoisting the vehicle into position. The first step involves removing the Oil Pan and Oil Pump and crankshaft oil deflector. Drive the crankshaft to bottom dead center (BDC) after you mark down the piston with cylinder information and connecting rod number for correct reassembly. The service requires using the cylinder bore ridge reamer (J 24270) to flatten out any significant ridges which may be found at the piston travel's upper point before continuing the work. Place a cloth over the piston and rotate the crankshaft to its lowest position. Remove the ridge from the cylinder ring at this time. Use the crankshaft to rotate it toward the highest point of the stroke before removing the cloth to clean metal debris from both the cylinder and piston. A suitable tool should be used to remove connecting rod nuts and cap and connecting rod and piston assembly afterwards. Inspection must occur for the piston as well as connecting rod bearings and connecting rod cap and crankshaft connecting rod journal while the cylinder bore requires honing followed by hot water detergent cleaning before the cylinder bores dry through swabbing with new engine oil. Before installing the piston and connecting rod assembly begin by applying oil to the cylinder wall and piston rings and position the crankshaft at bottom dead center. Then use the connecting rod bolt guide set (J 5239) and Piston Ring compressor (J 8037) before installation and verify that the piston arrow points toward the engine front. Place the connecting rod bearing caps into position after removing protective threads and tighten the nuts to 20 nm (115 ft. Lbs.) while using the torque angle meter (J 36660-A) to reach an additional 75-degree range. Check for binding conditions while also measuring connecting rod side clearance after reattaching the crankshaft oil deflector and Oil Pump and Oil Pan which should lead to lowering the vehicle and Cylinder Head installation.