Where is the relative position of the 4Y engine flywheel and crankshaft?
2 Answers
The flange at the rear end of the crankshaft is used to mount the flywheel. Between the rear journal and the flywheel flange, there is an oil baffle flange and oil return threads to prevent oil from leaking backward. Below is an introduction to the crankshaft: 1. Structure of the crankshaft front end: The polished surface on the crankshaft is the journal. The journals that support the crankshaft's rotation in the crankcase are the main journals, and their axes are all aligned. The journals offset from the main journal axis, used to connect the connecting rods, are called connecting rod journals (or crankpins), with a certain angle between them. There are lubricating oil passages machined between the connecting rod journals and main journals. 2. Oil passages inside the crankshaft: The parts connecting the connecting rod journals and main journals are called cranks (or crank arms). The connecting rod journals and cranks together convert the force transmitted by the connecting rods into the rotational torque of the crankshaft. There are transition fillets between the journals and cranks to increase strength. A connecting rod journal, the cranks at both ends, and the adjacent two main journals form a crank throw.
In a 4Y engine, the flywheel is directly mounted to the rear end of the crankshaft, precisely at the crankshaft flange, and securely fastened with bolts. The crankshaft connects to the pistons for rotation, while the flywheel helps store energy to ensure smooth engine operation. This design guarantees smooth power transmission during startup and reduces vibrations. If the position becomes misaligned—due to loose bolts or wear on the flywheel ring gear—the car may produce clicking noises or even fail to start. I recommend regular inspections, especially for high-mileage vehicles, to check for abnormal noises or vibrations. Additionally, engine overheating or poor maintenance can affect the alignment, so maintaining a healthy cooling system is crucial. Avoid DIY disassembly; it’s safer to have a professional shop inspect it with proper tools. Precise alignment is vital for extending engine life, and neglecting it may lead to more severe transmission issues.
