Komatsu 170-3 Series, Руководство по ремонту, Страница: 450 / 454

REPAIR AND REPLACEMENT OF PARTS
15-44
170-3 SERIES
(7)
TESTING AND INSPECTING OF CONNECTING ROD
TESTING AND INSPECTING
Unit: mm
1. Bolt
2. Washer
3. Cap
4. Dowel pin
5. Connecting rod
6. Bushing
Inspection item Judgement standards Remedy
A. Cracks Check for cracks with a color check or magnetic flaw detector Replace
B. Parallelism and torsion Replace
C. Clearance between
connecting rod bush-
ing and piston pin
Replace bush-
ing, roughness of
inside surface of
bushing: Max.
1.6S
D. Inside diameter of hole
at big end of connect-
ing rod Replace
E. Thickness of bearing
Measure parallelism a and torsion b
(After installing pin bushing)
Standard
size
Tolerance
Standard
clearance
Clear-
ance limit
Shaft Hole
68
-0.020
-0.026 +0.049
+0.030
0.030 – 0.075 0.075
Standard size Tolerance
115
+0.026
0
• Inside diameter of hole at big
end
• Without bearing
• Roughness of inside surface of
hole at big end: Max. 6.3S
• Clearance between crankshaft
journal (with bearing)
Standard
clearance
Clearance limit
0.058 – 0.132 0.132
Even if each part is within the repair
limit, if it is above the clearance limit,
replace the part (bearing, etc.)
Item Standard size Tolerance Repair limit
S.T.D 3.500
-0.029
-0.042
3.41
U.S 0.25 3.625 3.54
U.S 0.50 3.725 3.66
U.S 0.75 3.875 3.79
U.S 1.00 4.000 3.91
TESTING AND INSPECTING OF CONNECTING ROD
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