Fault detection cylinder block and crankshaft

Measure the diameter of the cylinder bore gauge (Fig. 3.37). Driving measurement is shown in Fig. 3.38. If the cylinder walls wear exceeds 0.08 mm, it is necessary to bore them to the next oversize and install the appropriate repair pistons. Even if only one cylinder is worn on the size of the repair process all cylinders. The connecting rods are replaced in the kit.

Thoroughly clean crankshaft. Inspect and crankpins of the crankshaft. Measure by a micrometer diameter necks and identify deviations from the roundness of each neck. The values of the repair sizes, permissible wear tolerance and roundness necks are given in Section. 3.1.1. At deterioration of necks, presence on them scratches or scratches, deviations from roundness all crankshaft journals processed for the next repair size in the repair shop.

Before reinstalling the crankshaft should be thoroughly cleaned, oil channels - clean and blow compressed air. Make sure there are no plugs in them. To do this with the help of oil can fill the hole in the oil channel oil - it should come out of another hole in the adjacent neck. Any blockage of the oil channel must be eliminated before installing the crankshaft.

Check the condition of the connecting rod bearing inserts. Signs of damage to the connecting rod bearing is a regular rhythmic loud knock on the part of the crankshaft. Its frequency depends on the speed of the crankshaft. This is especially good knock is heard at the engine load. It may be accompanied by a drop in oil pressure.

On the main bearing damage usually indicates a strong vibration, especially at high engine speeds. It is accompanied by a significant drop in oil pressure than when worn connecting rod bearings, and a loud thud. The bearing shells in good condition have a smooth uniform matt silver surface. Types of damage inserts are shown in Fig. 3.39. If the ear is damaged, and the crankshaft journals are in good condition, install new liners of the same size. When grinding the necks must have the appropriate repair inserts.

Damage liners can be caused by lack of lubrication oil in the presence of dirt and foreign particles, motor overload or corrosion. Before assembling the engine it is necessary to eliminate the cause of the release of their order pads. For example, one of the reasons is the operation of the engine at low speeds and high loads when the oil pump does not provide the normal pressure in the lubrication system and the oil is squeezed out of the labor-intensive areas. Frequent starts the engine and travel short distances lead to corrosion, since the engine does not fully warm water and condensate in its detail does not evaporate.

Check the condition of the crankshaft journals, working in contact with the seals.

Check the bearing clearance of the crankshaft with a round plastic rod Plastigauge. To do this, follow these steps:

-ochistite Liners beds of radical bearings, bearing caps and crankshaft journals;

- Install main bearing inserts beds in bed in its place;

- Set the crankshaft without pre-lubrication of its necks and bearing inserts;

- Cut 5 pieces of rod Plastigauge. They should be slightly shorter than the width of the necks;

- Set the bearing caps with inserts in its place;

- Tighten the crankshaft bearing caps to torque (see. Sect. 3.1.1). In no case do not rotate the crankshaft;

- Unscrew the crankshaft bearing cap number 1 and remove the cover;

- Deformed rod Plastigauge remove and attach it to the scale of the scale applied to the package, determine the scale gap (Fig. 3.40);

- Determine the value of the gap in the remaining bearings;

- Remove all traces of the rod to the crankshaft journals and liner;

Rinse with hot water under pressure all internal passageways and cavities of the cylinder. For assistance, contact the service station on land sinks. Blow cavities and channels the compressed air. Clean and blow compressed air all the threaded holes. If the damage turns banish threaded holes corresponding tap.

Inspect the cylinder block for cracks or corrosion.

Determine the clearance between the piston and cylinder using a stylus or subtracting from the bore diameter of the piston. If the gap is greater than required, replace the piston cylinders or processed until the next repair size with the installation of the respective pistons.