5.13.1. Removal, troubleshooting and installation of camshafts

Camshafts replace in the following cases:
– pressure drop in the engine lubrication system. The increased wear of necks of camshafts and nests in cases of bearings of camshafts happens the reason of this malfunction often. At wear of nests replace a block head assembled as nests process together with the case of bearings installed on a head;
– knock of valves at serviceable hydropushers (see. "Check and replacement of hydropushers") in the valvate mechanism. It is caused by the increased wear of cams of the camshaft because of use of low-quality engine oil or damage of an oil filter.
It will be required to you: the same tools, as for replacement of oil scraper caps, except for those which are required directly for their replacement (tools only for preparatory operations are used), and also a micrometer and a nutromer.
1. Remove camshafts from the engine (see. "Replacement of oil scraper caps").
2. Examine camshafts. On the working surfaces of necks 2 teases, zaboina, scratches, an aluminum navolakivaniye from nests of bearings in cases and a head of the block are not allowed. On working surfaces of cams 1 teases and wear over 0,5 mm, and also wear of cams in the form of a facet are not allowed. Replace a shaft with the found defects.
3. In the workshops equipped with special devices and tools it is possible to check a radial beating of necks of the camshaft (it should not exceed 0,02 mm).
4. Measure diameters of basic necks of a shaft. They have to make 23,915–23,931 mm.
5. Examine the case of bearings …
6. … and support of camshafts in a block head. Cracks on the case are not allowed. On working surfaces of support under necks risks, scratches, teases, excessive wear are not allowed.
7. Install the case of bearings of camshafts on a head of the block and tighten bolts of its fastening the recommended moment (see the appendix 1). Measure internal diameters of support of the case of camshafts. They have to make 24,000–24,025 mm.
8. Calculate on a difference of the sizes gaps between necks of shaft and support. For new details gaps have to be equal to 0,069-0,11 mm. If after operation gaps exceed 0,2 mm, replace camshafts. If after replacement of shaft gaps exceed the most admissible value, replace a head of the block of cylinders assembled with the case of bearings of camshafts.
9. Install camshafts and all removed details as it should be, the return to removal.

Note
Apply on the surface of a head of the block of cylinders interfaced to the case of bearings of camshafts, sealant like "Loktayt-574" in the form of the roller with a diameter of 2 mm.