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Checking crankshaft
Check the crankshaft must be performed in this order: - To conduct a thorough inspection of the crankshaft for wear and deformation, to measure the cervix main and connecting rod bearings. Crankshaft grinding can be subjected to four times, so the crankshaft can be fitted with inserts of the repair sizes; - The crankshaft clamp on a lathe (or put it on the prism, the substituted under extreme neck main bearings) and check runout on the average radical neck with a measuring indicator. Runout should not exceed 0.06 mm, otherwise the crankshaft must be replaced. The gap in the main and connecting rod bearings should be measured in the following order: - Set in the bearing housings of the cylinder liners without appropriate cover, lubricate the threads of the fastening screws and bolts alternately to produce a first torque 55 Nm and then tighten them to the 90-100 ?�. Main bearing caps are made with a certain bias, so can be installed in only one, the correct position;
| Fig. 77. Metering holes crankshaft bearings
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- Measure the diameter of each bearing in the direction of axes A, B and C indicated in Fig. 77, and record the results. If any of the measurements exceeds or other detected output conical bearing bore, the bearing cap of the sandpaper can be increased to a maximum of 0.02 mm; - Remove all main bearing caps, install liners are pre-should be thoroughly cleaned, and then install the bearing cap with insert and tighten the fixing bolts duly bearing caps (see above).
| Fig. 78. Measurement of the inner diameter of the bearing shells by means Nutromer
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- Measure the diameter of each bearing, as shown in Fig. 78, and record the results of measurements; - From the obtained values of the diameters of the bearing pads should be installed to deduct the diameters of the crankshaft main journals. The results and will mean working air gap, which should not be in the range 0,031- 0,073 mm for the indigenous as well as for connecting rod bearings of the crankshaft. Wear limit is 0,080 mm. If necessary, these gaps may be adjusted by setting different inserts repair sizes. The company Mercedes-Benz offers the bearing shells of the crankshaft four repair sizes. Other works do not differ significantly from each other and set out above. The following are guidelines for the selection of loose leaves of radical bearings.
| Fig. 79. Designation of hole tolerance crankshaft bearing (indicated by arrows)
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Inserts crankshaft bearing selected and installed in accordance with markings applied punch near the bearing seat in the engine block. Marking location shown by the arrows in Fig. 79. On the lateral edges of the inserts applied to the corresponding color code (see. Below). This marking must be followed, although it should be noted that for the repair inserts offer exclusively with green or red markings. Inserts mounted in the crankshaft bearing caps, taking into account the diameter of the main journals of the crankshaft. For this reason, every knee shaft color-coded (blue, green or red dot):
The diameter of the number of color Cervical mm marking nakernennyh points 62,500-62,506 1 blue 62,506-62,513 2 green 62,513-62,519 3 red
| Fig. 80. Colour code stamped on each knee shaft
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Marking location indicated by the arrows in Fig. 80.
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