4.2.14. Survey of the crankshaft

Measurement of a longitudinal side play of the crankshaft


1. Measurement of a longitudinal side play of the crankshaft has to be performed at the crankshaft which is still installed in the block the cylinders / case however freely moving (address the Section Removal of the Crankshaft).

2. Measurement of a longitudinal side play is performed by the dial measuring instrument by a touch of its contact probe to a crankshaft end face. Completely push the crankshaft from the measuring instrument aside, for - expose those zero on the measuring instrument at a contact of the contact probe to a crankshaft end face. Then completely push the crankshaft towards the measuring instrument and take readings of the indicator. The result has to be compared with brought in the Specification x values then the decision is passed whether persistent washers have to be replaced.

3. In case of impossibility to use the dial measuring instrument, the procedure of measurement can be made by means of lezviyny shchupovy measuring instruments. At first completely push the crankshaft towards a flywheel, then by means of the shchupovy measuring instrument measure a gap between a cheek of a crank of the third bearing and a persistent washer of the central radical bearing.


During the work with compressed air use goggles! Check whether oil openings are well cleaned, use for this purpose a tubular nozzle of a container with a cleaner or other suitable probe. Openings should not be hammered.


1. Make cleaning of the crankshaft by means of kerosene or other suitable solvent, carefully dry it, whenever possible using compressed air.
2. Make sure that on bearing necks or other bearings and on bearings of a rod there is no uneven wear, scratches, pointed corrosion and cracks.
3. Wear of bearings of the lower head of a rod usually is followed by accurate metal knock during the operation of the engine (it is especially clear heard at a car start of motion with a small speed), and also some falling of oil pressure.
4. Wear of radical bearings usually is followed by strong vibration and a roar of the engine - increasing at increase in turns of the engine - and besides some reduction of pressure of oil.
5. Make sure of smoothness of necks of bearings by stroking by their fingers. Existence of a roughness (which usually is followed by obvious wear of bearings) indicates the need pro-points (if it is possible) or replacements of the crankshaft. Pay attention that the crankshaft pro-point to the amount of the first repair is possible without retraining of a shaft, however the further pro-point demands retraining (Tenifer's method).
6. In case the crankshaft was exposed to a pro-point, check whether there are no agnails around oil openings of the crankshaft (usually openings have facets therefore at accurate carrying out a pro-point of problems with agnails should not arise). Remove all available agnails with a thin file or a scraper and carefully clean oil openings as it was described above.

7. By means of a micrometer measure diameters of necks of radical bearings and bearings of the lower head of a rod, compare results to the values given in Specifications. By measurement of diameter in several points it is possible to determine a neck section ellipsoidnost by perimeter of section of a neck. Perform measurements on each end of a neck near crank cheeks for definition of existence of conicity of a neck. Compare results to the values given in Specifications.

8. Examine contact surfaces of epiploons on each end of the crankshaft regarding detection of wear or damages. In case on the surface of the crankshaft as a result of wear the deep flute was formed, consult at specialists in capital repairs of the engine; it is in certain cases possible to eliminate such malfunction, otherwise the crankshaft has to be replaced.