How to Properly Disassemble and Assemble the Crank Connecting Rod Mechanism?
3 Answers
Remove the oil filter screen, float, and oil pump, then detach the crankshaft pulley. Take out the intermediate gear. Extract the intermediate shaft, and remove the front oil seal and front oil seal flange. Check the axial clearance of the connecting rod big end, remove the connecting rod bearing cap, and pull out the piston connecting rod assembly from the cylinder. Note that the marks on the connecting rod, connecting rod big end cap, and piston should match the cylinder number. If there are no marks, they should be re-stamped. The maximum axial clearance is 0.25mm. If it exceeds this value, the thrust washer should be replaced.
Disassembling and assembling the crankshaft connecting rod mechanism is something I know all too well. After decades of tinkering in the garage, safety always comes first. Let the engine cool overnight to avoid burns. Then disconnect the negative battery cable to prevent arc sparks. When removing cylinder head bolts, note their positions to avoid misalignment during reassembly. Gently extract the piston and connecting rod assembly, thoroughly cleaning bearing surfaces and bolt holes with a soft brush and gasoline. Check connecting rods for bends or cracks, and ensure piston rings move freely. During installation, replace with new gaskets and use a torque wrench to tighten connecting rod cap bolts to manual specifications in two to three even increments, avoiding over-tightening or looseness. Don’t forget to check crankshaft clearance. After completion, perform a cylinder pressure test upon startup. I always say this job requires steady and methodical work—one slip-up could seize the engine and total the entire vehicle.
As a car novice, I sweated nervously during my first attempt at disassembling the crankshaft connecting rod. Basic tools prepared: socket set and torque wrench. The steps involved removing spark plugs and wires, then taking off the cylinder head and bolts. Remember to mark each component's position to avoid confusion during reassembly. Used cleaner to wash away oil sludge during the cleaning phase and checked piston ring integrity. When installing the connecting rod, ensure proper alignment with the crankshaft direction - don't reverse it, and tighten bolts evenly to recommended torque. Messed up the orientation during my first attempt, fortunately a friend came to rescue, otherwise could have damaged the engine. Surface cleaning is crucial - skipping it leads to carbon buildup issues. After completion, did a test engine start - ran smoothly but felt uneasy inside, would advise beginners to start with simpler tasks first, this DIY carries significant risks.
