4420300960 engine rod bearing is a part of Mercedes. How to diagnose abnormal noise of 4420300960 engine rod bearing? Below are the judgments and solutions compiled by the editor of Guangzhou Hui Yuan Mechanical Electrical Co., Ltd. for you. Let us take a look.

Abnormal sound failure phenomenon of 4420300960 engine rod bearing

The sound is relatively small at idling speed, and more pronounced at medium speed. The sound increases when the engine is suddenly accelerated; when the engine load increases, the sound increases; when the engine water temperature changes, the sound does not change; the sound is significantly weakened after the fire is cut off Or disappear.

The possible causes of the failure of the 4420300960 engine rod bearing:

(1) 4420300960 engine rod bearing and connecting rod neck are severely worn, which makes the radial clearance too large;

(2) The connecting rod cover bolts are loose or fall off;

(3) 4420300960 conrod bearing was burned or fell off;

(4) The inner hole of the small end of the connecting rod is out of round, and the connecting rod neck is in poor contact with the connecting rod bearing;

(5) The main oil passage of the crankshaft is blocked, the filter collector and the filter are blocked, the bypass valve fails, the oil pump fails, the oil pressure is insufficient, and the bearing is poorly lubricated.

The solution to the failure of the 4420300960 engine rod bearing:

(1) Disassembly and inspection, if the type of 4420300960 engine rod bearing is wrong, replace it; if the direction of the connecting rod cover is wrong, reinstall it;

(2) Check whether the tightening torque of the connecting rod cap bolts is qualified, if it is loose or the torque is unqualified, reinstall and tighten;

(3) Decompose and check the 4420300960 conrod bearing to confirm whether the bearing has a surface layer peeling off, and if it is defective, replace it immediately;

(4) Disassemble and check whether the connecting rod bearing is abnormally worn. If there is, check the oil system immediately to see if the oil supply is normal.

Routine maintenance of engine rod bearings

(1) Check the 4420300960 engine rod bearing for defects such as peeling or scratches. If it is damaged, replace it with a new one.

(2) Check the bending and twisting of the connecting rod with a feeler gauge on the connecting rod tester. If the connecting rod is bent or twisted, the connecting rod must be corrected or replaced with a new one.

The maximum bending limit value of 4420300960 engine rod bearing is generally: 0.05mm/100mm; the maximum twisting limit value is generally: 0.05mm/100mm.

(3) Measure the connecting rod gap.

Install the plastic gap gauge on the connecting rod journal. Note that the plastic gap gauge cannot be placed on the oil hole. Tighten the connecting rod cover with the specified torque, being careful not to turn the connecting rod or crankshaft.

Then remove the connecting rod cover and check the width of the widest point of the squashed plastic gap gauge.

If the connecting rod journal gap corresponding to this width exceeds the specified limit value, the crankshaft connecting rod journal should be ground. The bearing clearance of the engine rod bearing is generally 0.012~0.09mm.

(4) Check the axial clearance of the 4420300960 engine rod bearing.

Use a feeler gauge to measure the axial clearance between the connecting rod and the crankshaft. When measuring the axial clearance, press the connecting rod axially to either side of the crankshaft, and then measure the clearance on the other side. If the axial clearance of the connecting rod exceeds the specified value, the connecting rod or crankshaft or both should be replaced. The axial clearance of the engine rod bearing is generally 0.13~0.38mm.

The above is the failure inspection and solution of 4420300960 engine rod bearing. Do you understand it?