Yaroslavl ???-236, Maintenance Manual

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2.8.22 Fastener nuts of the cylinder heads should be tightened at the cold
engine in consequence specified in the chapter Engine assembling: from the middle to
the sides crosswise previously lubricated the thread with the oil no less than in three
steps:
I step – 39-49 N*m (4-5 kfg·m);
II step – 118-147 N*m (12-15 kfg·m);
III step – 216-235 N*m (22-24 kfg·m);
2.8.23 Installing valve rocking arms adjusting screws should be screwed until hard
stop into the rocker (rods should be released). Bolt tightening of the rocker arms support
should be performed with the torque 12-15 kfg*m.
dimension of the clearances between the toe of the rocker and the valve should
be as follows:
- for induction and eduction valves 0.25-0.3 mm;
Clearance adjustment in the valve operating mechanism should be
performed according to the methods described in the chapter Expansion gaps
adjustment in the valve operating mechanism - Operation manual 236.3902150-
Б
RE.
To abject the clearance one need to ease the jam nut of the adjuster screw, to put
the gauge corresponding the thickness of the upper limit of the clearance, into the
clearance and rotate the screw with the screw driver till it touches the gauge. Then
protecting the screw with the screw driver from the crank, to tighten the jam nut and to
check the clearance according to the gauge limits.
If the clearance are adjusted correctly gauge with the thickness corresponding the
lower limit of the clearance should run free and gauge with the thickness according to the
upper limit of the clearance should have constraints.
During the following rotation of the crankshaft clearance changing may be allowed
till the limits 0.20-035 mm because of the surface runout of the joining parts of the valve
operating mechanism.
2.8.24 Tightening of the injector yoke nut should be performed with the torque
5-6.2 kfg*m.
2.8.25 One should install the rubber reinforced lip-type seals at the shafts in
accordance with the requirements of the GOST 8752-79.