3.2.2.1. Check and adjustment of backlashes of valves

THE GENERAL DATA

Camshaft fixing

1 – a blocking bolt

The backlash of valves is necessary for regulating only in cases of detection of the raised expense of fuel, wrong adjustment, replacement or operational development of valves, replacements of pushers or a camshaft.

Check

The backlash of valves is checked at the cold engine.

PERFORMANCE ORDER

1. In engines without pressurisation take the air channel. 2. In engines with a turbo-supercharging take a pressurisation radiator. 3. Uncover heads. 4. Unscrew candles накаливания. 5. Remove the right pulley and a casing. 6. Check up backlashes of valves in two stages:       – Finish to a condition of opening of the valve of the cylinder №4. Check up backlashes of valves of cylinders №: 1 – inlet, 1 – final, 2 – inlet, 3 – final;       – Finish to a condition of opening of the valve of the cylinder №1. Check up backlashes of valves of cylinders №: 4 – inlet, 4 – final, 3 – inlet, 2 – final.

Backlashes of valves (the engine cold)

The inlet valve	0,15 mm
The final valve	0,30 mm
The admission	± 0,08 mm

Adjustment

PERFORMANCE ORDER

1. Check up backlashes of valves according to the method described above and write down the measured values. 2. Loosen the driving a belt of a camshaft also remove it from a camshaft pulley. 3. Block a pulley of a camshaft by means of a special bolt and unscrew a fastening bolt. 4. Remove a pulley. 5. Remove covers of bearings of a camshaft and a camshaft. 6. Remove pushers and establish them one after another. 7. Take adjusting plates and measure their thickness. 8. Define a necessary thickness of adjusting plates:       – If the measured backlash is too small, it is necessary to establish a plate of a smaller thickness (the tab. the Example see);       – If the measured backlash too big it is necessary to establish a plate большей thickness (see tab. the Example). The prevention After replacement of one of system details timing or after grinding in of valves it is necessary to establish 8 regulating plates in the thickness not less than 2,425 mm. 9. Establish pushers with adjusting plates of a necessary thickness. 10. Establish new sealing rings. 11. Establish a camshaft pulley. 12. Check up camshaft installation. 13. Establish and adjust a tension of a gear belt. 14. Establish a casing of a distributive drive. 15. Establish a sealant, fix a cover of a head of the block of cylinders and other dismantled details.

EXAMPLES OF ADJUSTMENT OF BACKLASHES OF VALVES

Example And

Demanded backlash	0,15 mm (admission)
The measured backlash	0,25 mm
Difference	0,10 mm
Thickness of the established plate	2,35 mm
Thickness of a plate which should be established	2,45 mm
The turned out backlash	0,15 mm

Example In

Demanded backlash	0,30 mm (release)
The measured backlash	0,25 mm
Difference	-0,05 mm
Thickness of the established plate	2,925 mm
Thickness of a plate which should be established	2,875 mm
The turned out backlash	0,30 mm