Carefully check a cranked shaft on existence of damages and make exact measurements of necks of radical and shatunny bearings. And shatunny necks of a cranked shaft it is possible to chisel necks of radical bearings three times then on them loose leaves of bearings of the smaller (repair) size are established.

Fig. 442. Measurement palpation of a cranked shaft

Clamp a cranked shaft in the lathe (fig. 442) or clamp both necks of a shaft in prisms and by means of the indicator measure palpation on an average neck. Palpation should not be more than 0,06 mm. Otherwise it is necessary to replace a shaft. Now there is no way of editing of a cranked shaft.

Measure palpation of radical bearings and shatunny bearings if the car with this shaft already has big run. In car-care center «Plastigage» — a plastic wire is for this purpose used, however, as shows experiment, it happens rather difficult to get. If you have no possibility to get such «a measuring wire», the same operation can be done in a different way which is described further. If you carry out measurement by means of «Plastigage», act as follows:

- carefully clear loose leaves of bearings and put them in beds of bearings of the block of cylinders or in rods. Well insert "noses" of loose leaves of bearings into the directing;

Fig. 443. Put a slice of a wire of "Plastigage" in the shown direction on necks of bearings

- put on «Plastigage» slice on a neck of each radical bearing ( fig. 443 , it is shown by an arrow) and establish a cover of the radical bearing with the enclosed loose leaves of the bearing. Tighten bolts the moment of an inhaling of 65 N · m. After that any more do not rotate a shaft;

- for check of gaps of shatunny bearings get a rod on a shatunny neck of a cranked shaft, and put «Plastigage» on the top part of a shatunny neck of a cranked shaft. Establish a bearing cover with the loose leaf (again pay attention to the correct arrangement of «directing noses») and tighten nuts the moment of an inhaling of 30 N · m. As the shaft cannot be turned more, measurements are carried out on two shatunny bearings being in NMT;

- unscrew covers on radical bearings; on shatunny bearings in turn turn on both covers;

Fig. 444. Measurement of the flattened-out delays of "Plastigage" by means of a measuring ruler

- by means of the measuring ruler entering into a set of "Plastigage", measure the crushed strips of a material in the widest place, having put a ruler on plastic strips (fig. 444) . If this size exceeds 0,17 mm for radical bearings or 0,12 mm for shatunny bearings, it is necessary to establish new loose leaves of bearings, considering was made earlier or not polishing of necks.

If you have no plastic wire of "Plastigage", and you have some experience of similar measurements, it is possible to measure palpation of radical and shatunny bearings in the way described further that will allow you to draw the corresponding conclusions.

Establish covers of bearings together with the enclosed loose leaves of bearings in the block of cylinders, and tighten bolts the moment of 65 N · m. Surely track, that loose leaves were established in the initial places. If measurements of shatunny bearings are carried out, insert loose leaves into rods and covers of rods and tighten covers old nuts the moment of 30 N · m.

Fig. 445. Measurement of diameter of the inserted loose leaves of the bearing by means of the indicator. Measurements are carried out in the direction A and B, and also in the direction 1 and 2

Measure in turn bearings — the measurement scheme on fig. 445 . Pay special attention to the direction of measurements of A and B, and also a place of measurement 1 and 2. Write down results of measurement of each separate bearing.

Fig. 446. Measurement of diameter of necks of the radical bearing. Carry out measurements in the places shown by shooters. Necks of shatunny bearings can be measured as

In turn measure diameter of all necks of bearings by a micrometer. Thus again pay attention to places of measurements which are specified fig. by 446 shooters. Write down results of measurement of each neck of bearings.

Results of measurement of diameter of bearings subtract from internal diameter of openings of bearings. As a result you receive palpation of the radical and shatunny bearings which value should correspond to the values specified above.

To check palpation of shatunny bearings, turn a cranked shaft and measure the following two necks shatunny necks as it was described.