Yaroslavl ???-236, Maintenance Manual

Page: 90 / 270

Technical requirements for the repaired assembly unit
Number of the
defect
1 Tolerance of circularity and longitudinal section profile of the surfaces J and I – 0.005 mm
2
2 Circularity tolerance of the surfaces Д and Е – 0.007 mm
6, 7
3 Symmetry tolerance to the surface of the hole Ш relatively to the surface Б – with radius 0.12 mm
5.10
4 Positional tolerance of the hole
Э relatively to the surface М – with radius 0.05 mm
4, 9
5 Roughness of the surfaces according to the GOST 2789-73 should not be more than:
-
surfaces Ж and И – Ra 0.25 micron
-
surfaces Б and М – Ra 1.25 micron
2
4, 5
6 Gear position III and counter balance position II before the pressing on should be heated to the temperature
from 408 to 458 К (from 135 to 185°C)
11, 13
7 Gear retaining nut position III and counter balance position II should be tightened with the moment of a force
from 180 to 300 Nm(from 18.0 to 30.0 kfg m) and locked using the bending of the locking washer edge into the
nut slot. if there is a marking on the nut it should be installed with the marked side outward
11, 13
8 Back oil deflector position IV should be pressed on the crankshaft bearing so that
dimension Р to be from 0.5 to 1.5 mm and locked using the pressing of the oil deflector edge in four slots at the
crankshaft bearing 15