Deutz diesel engine FAQ
22. Why did the connecting rod screw break and break the body?
After all processing of side rod bolts is completed, magnetic flaw detection must be carried out one by one, and their chemical composition, mechanical properties are also strictly controlled. The reasons why the side pole bolts break are:
(1) The connecting rod bolts were not tightened to the specified working torque during assembly. The tightening torque of the 4102 machine is 100-120N.m. The connecting rod bolts became loose during long-term use and were not tightened in time;
(2) The connecting rod shoe melts for some reason, and the gap between the connecting rod journal and the connecting rod shoe increases, resulting in impact force and breaking;
(3) The connecting rod locking piece is damaged or not locked firmly;
(4) The threads of the connecting rod body and connecting rod bolts are bruised or unclean. Although the torque is felt to be larger when the connecting rod bolts are rotated, the specified torque value is not actually reached, resulting in a false kilogram value. In this way, the connecting rod body and connecting rod bolts are damaged. There is a gap between the connecting rod tiles, causing it to be broken during operation;
(5) The connecting rod bolt is tightened too much, and the tightening torque exceeds the calibration range, so that the force on the connecting rod bolt exceeds the elastic limit of the bolt material.
23. Why is the amount of lubricating oil on the rocker arm shaft too small or no lubricating oil?
The reasons why the rocker arm shaft has no lubricant are:
(1) The oil pump does not work or works poorly, and there is no oil pressure or low oil pressure;
(2) The oil hole in the rocker arm seat is blocked;
(3) The oil hole in the arm base is clogged with iron filings and debris and the engine oil cannot be supplied;
(4) During repair and maintenance, the assembly position of the rocker arm seat was reversed due to assembly errors, and the oil hole was blocked;
(5) The front bushing of the camshaft moves and the position of the oil hole deviates;
(6) The position of the pump oil groove on the camshaft is offset or the width, depth and length of the pump oil groove are insufficient;
(7) The rocker arm seat bolts with oil holes are not tightened, and engine oil leaks from the bottom of the rocker arm seat;
(8) During assembly, the oil hole of the rocker arm shaft and the oil hole of the rocker arm seat are not aligned, or the rocker arm shaft locking screw is loose, and the oil holes cannot be aligned with each other.
24. Why does the rocker arm shaft break?
The reasons for rocker arm shaft breakage are:
(1) The rocker arm seat compression nut is loose and the tightening sequence is improper;
(2) The rocker arm shaft is poorly lubricated and seized;
(2) During maintenance, the arm base is installed backwards and the lubricating oil in the cylinder head oil passage cannot come up;
(3) The rocker shaft lubricating oil hole is not drilled with sufficient strength on one side during the drilling process;
(4) There were cracks on the edge of the oil hole during the heat treatment of the rocker arm shaft.
