1, thoroughly clean the crankcase and its internal oil, must carefully check and make sure: crankcase oil clean and smooth, internal casing horizontal clapboard, etc all can not have crack, the installation of sealing surface must not have scratches and damage.
　　2, carefully check the crankcase cylinder liner surface, to ensure the installation seat surface level off is smooth, no bruising, scratches or other defects. Check each cylinder liner seat surface flatness, between the crankcase cylinder liner surface within the total length of the flatness shall not be greater than 0.1 mm.
　　3, crankcase spindle tile bottom hole if there is a slight scratch, strain, can use the fine oil stone or 00 number use sand paper after grinding smooth. Serious scratch, strain or diaphragm plate has a crack, the following methods can be used to repair:
　　(1) minor scratches, injury or loss of FANADE Bearings - 6305-RZ Bearings http://www.fagbearings-hk.com/newproduct/NACHI-6305-RZ-bearings-19957.html , the can by spindle in tile bottom hole reaming with tile.
　　(2) if the cut and scratched strain, box deep diaphragm plate has a crack or axle bush in circles, can repair by the method of thermal spraying. Note: the thermal spraying must be used to mature, advanced high-tech technology to complete, after spraying must be to high precision boring processing of bearing shell bottom intake, to ensure that the spindle tile bottom hole alignment requirements.
　　4, the main bearing cover damage, if any, from all of the diesel engine main bearing cap must be replaced at the same time, can use high precision bore hole with tile or thermal spraying methods such as high precision boring after repair.
　　5, the main bearing cover assembly must be a drunbility, shall not be interchangeable. The order number is: start from the flywheel end: 1-2-3-1-2-3-7 (to fan section)
　　6, check the spindle tile bottom hole, CAM shaft hole in the full length in the two adjacent hole axis alignment must conform to the requirements of the way in, air-cooled diesel engine.
　　7, the main bearing cap bolts, cylinder head bolt strain or crack, must be replaced. Cylinder head bolt elongation than specified value, must also be replaced.
　　8, cylinder head bolt hole and threaded hole to allow other reaming set set of processing, but the reaming tap should keep the original size.
　　9, crankcase cover seal bad or loose wall everywhere, blocking cover should be changed, and the sealing glue.
　　After 10, crank spindle watts wear overrun, must be in accordance with the requirements of the repair level, according to the size of grinding crankshaft main journal for replacement, to ensure that the crankshaft journal and spindle watts of fit clearance conform to specified requirements.
　　11, CAM shaft lining and the CAM shaft neck of fit clearance must meet the requirements of limit, exceed the limit of size must be replaced. When installation should pay attention to bushing oil hole on the crankcase oil hole is.
　　12, crank shaft and the CAM shaft bushing wear not overrun, but there is surface scratches, hemp pit corrosion point, the phenomenon such as burning-out, must be replaced.
　　13, crank shaft and the CAM shaft bushing without scratches, corrosion, or other damage, color can be used to check the method to determine whether can continue to use. If the shaded area is small and not uniform, must be grinding crankshaft.
　　14, clean and check the crankcase ventilation device, such as crack, damage or damaged, must be paid to the repair or replacement.
　　15, breathing apparatus, any injury or damage, must be repaired or replaced. If you can't judge of respirator, during commissioning confirmed: high speed diesel engine idling, crankcase emission measurement pressure, guarantee the gas pressure in the range of 2 ~ 6 mbar, exceed this value must be repair or replace the respirator.
16, check engine installation leg, the oil pan, flywheel shell, after the oil seal cover plate, attachment bracket and other components, such as crack, deformation and damage, to be replaced.