Elements of the gas distribution mechanism of the M30 series engine
1 - rocker axis;
2 - cork;
3 — axis;
4 - lining;
5 - spring cup;
6 - outer spring;
7 - inner spring;
8 - oil deflector cap;
9 — upper spring cup;
10 - crackers;
11 - locking bolt;
12 — spring;
13 — adjusting washer;
14 — rocker arm;
15 - mounting bracket;
16 — thrust ring;
17 — bolt;
18 - eccentric;
19 - washer;
20 - nut;
21 — inlet valve;
22 — exhaust valve.
Valve unit components of the M70 series engine
Remove the cylinder head.
Remove the camshaft.
Remove the rear cylinder head cover.
Remove the mounting brackets from each rocker arm.
Note: There are several types of brackets. Wire brackets are installed on each side of the rocker arm, spring brackets run along the rocker arm.
Before removing the rocker arm shafts, measure the radial clearance of each rocker arm and compare the result with the required values (0.015-0.051 mm).
Without moving the rocker arm along the axis, try to turn the rocker arm on it first in one direction and then in the other. The radial clearance is the total displacement of the end of the rocker arm facing the camshaft. If the clearance is greater than required, the rocker arm bushing, the axis, or both of these elements require replacement.
Disassembling the cylinder head involves removing the intake and exhaust valves and associated parts.
Before removing the valves, be prepared to label them and store them separately along with the associated parts so that when reassembling they can be installed in their original locations, in the same guides.
Compress the first valve springs with a valve spring compressor and remove the valve cotters.
Carefully release the compressor and remove the springs and spring seat.
Pull the valve out of the cylinder head, then remove the seal. If the valve is stuck in the guide (and it can't be pulled out), push it back into the cylinder head and file down the area around the retainer groove with a fine file.
Repeat this operation with the remaining valves. Remember to fold and store the parts of each valve separately.
To quickly disassemble the valve assembly, you can use the following method:
Place an old piston pin on the top valve plate and hit it with a hammer.
Warning: Be careful. This will cause crackers to pop out and the springs to "jump".
Remove the valve components as described above.
Note: A tool is required to install the valves.
After the valves are removed, the cylinder head must be thoroughly cleaned and inspected. If the engine is being overhauled, finish disassembling the engine first, and then begin cleaning and inspecting the cylinder head.