4.19. Camshaft replacement

Camshaft replace in following cases:

– Pressure in system of greasing of the engine has fallen. The raised deterioration of necks of a camshaft and nests in the case of bearings of a camshaft happens the reason of this malfunction often. In this case a camshaft replace simultaneously with the case of bearings;

– Knock of valves at serviceable hydrosupport of levers of a drive. It is caused by the raised deterioration of cams of a camshaft because of application of poor-quality engine oil or damage of the oil filter. Thus basic surfaces of levers of a drive of valves with which in this case it is necessary to replace simultaneously with a camshaft are usually damaged also.

It be required to you: keys «on 10», «on 13», «on 17», «on 24».

1. Remove the case of bearings of a camshaft together with shaft («Replacement of hydrosupport of levers of a drive of valves» see).	2. Disassemble the case of bearings of a camshaft for what turn away two bolts of fastening of a persistent flange of a camshaft...

3.... Also take out a persistent flange from проточки in a forward basic neck of a shaft.	4. Take out a camshaft from the case of bearings, shifting it forward.

THE NOTE At extraction of a camshaft from the case of bearings be cautious – do not damage sharp edges of cams of a surface of support under camshaft necks.

5. Examine a camshaft. On working surfaces of necks teases, забоины, scratches, наволакивание aluminium from the case of bearings are not supposed.	6. On working surfaces of cams deterioration over 0,5 mm, and also teases and deterioration of cams in the form of a facet is not supposed. A shaft with the found out defects replace.

7. Measure diameters of basic necks of a shaft. They should be (considering from a lobby):

1 – 45,915–45,931 mm;

2 – 45,615–45,631 mm;

3 – 45,315–45,331 mm;

4 – 45,015–45,031 mm;

5 – 43,415–43,431 mm.

8. Examine the case of bearings of a camshaft. Cracks on the case are not supposed. On working surfaces of support under necks risks, scratches, teases, excessive deterioration are not supposed.

9. Measure internal diameters of support of the case of a camshaft. They should make (considering from a lobby):

1 – 46,000–46,025 mm;

2 – 45,700–45,725 mm;

3 – 45,400–45,425 mm;

4 – 45,100–45,125 mm;

5 – 43,500–43,525 mm.

If backlashes between shaft necks (see operation 7) and support exceed 0,2 mm (limiting deterioration), replace the case and if necessary a camshaft.

10. Establish a new camshaft and the case of bearings, and also all removed knots and details in an order, the return to removal.

NOTES Before camshaft installation in the case of bearings grease working surfaces of necks and cams of a camshaft with engine oil.

Fig. 4.6. An order of a tightening of nuts of the case of bearings of a camshaft

Nuts of fastening of the case of bearings tighten in an order shown on fig. 4.6 («Replacement of hydrosupport of levers of a drive of valves» see), the moment specified in enc. 1.