Views: 456 Author: Site Editor Publish Time: 2026-04-13 Origin: Site
The Mercedes M264 engine, as the mainstream 1.5T/2.0T turbocharged model of Mercedes Benz, requires extremely high precision in crankshaft assembly. The crankshaft related bolts are tightened using torque and angle, and most of them are disposable bolts. Strictly following the specifications can ensure stable engine operation, no abnormal noise, oil leakage, and bearing damage problems.
1、 Specification for torque of main bearing bolts
The main bearing bolt is the core fastener that fixes the crankshaft. For M264 engines, this bolt must be brand new and must not be reused. When installing, first reinstall the bearing cover in its original position and tighten it step by step in a symmetrical order from the middle to both sides. The first step is to pre tighten the torque to 36N · m, and the second step is to continue rotating 120 ° on the basis of pre tightening to complete the final tightening. During the tightening process, it is necessary to manually rotate the crankshaft multiple times to confirm that there is no jamming and the resistance is normal, in order to avoid deformation of the crankshaft or burning of the bearing due to uneven torque.
2、 Torque specification for connecting rod bolts
Connecting rod bolts are also disposable torque yielding bolts and must be replaced after disassembly. Apply a small amount of engine oil to the bolt threads during installation to ensure accurate torque transmission. Pre tighten with 30N · m first, then rotate 90 ° to achieve the standard tightening state. During operation, it is strictly prohibited to tighten it all at once, nor to increase the torque arbitrarily, to prevent deformation of the connecting rod and bolt breakage, and to ensure stable fit between the piston connecting rod group and the crankshaft.
3、 Torque of the crankshaft front pulley bolt
The crankshaft pulley bolt is responsible for fixing the damping pulley, which directly affects the smoothness of crankshaft operation. The standard tightening torque for M264 bolt is 115N · m. During installation, a special tool should be used to lock the crankshaft to prevent inaccurate torque caused by rotation. The bolt threads need to be cleaned and lubricated, tightened to the correct position in one go according to the standard, and cannot be adjusted repeatedly to avoid loosening and causing malfunctions such as abnormal noise and timing misalignment.
4、 Torque of flywheel bolts and other accessories
The bolts of the flywheel at the rear end of the crankshaft are tightened diagonally and uniformly, with a standard torque of 65 to 70N · m, to ensure a tight fit between the flywheel and the crankshaft flange and no jumping during operation. The torque of accessory bolts such as the crankshaft front oil seal cover and timing cover plate is relatively small, generally controlled at around 10N · m, to prevent excessive tightening from causing deformation of the housing and oil leakage.
All torque operations must be performed using calibrated and qualified torque wrenches and angle gauges, while the engine is cold. After assembly, check the smoothness of the crankshaft rotation and proceed with subsequent assembly only if there are no abnormalities to ensure the reliable operation of the M264 engine crankshaft system.
