Komatsu 4D98 Series Shop Manual page 73

4. Engine Body
(5.4)
Piston
0
Especially clean the combustion sur-
I
face, circumference, ring grooves and
piston pin bosses, and check after re-
moving any carbon deposit. Any burr at
a ring groove or snap ring groove shall
be removed. If crack is suspected, in-
spect by color check.
Piston outside diameter measurement
Measure the long diameter at H mm
from the bottom end of the piston of the
oval hole in the vertical direction to the
piston pin hole.
I
l
Piston outside diameter
Standard Limit Measurement position (H)
4TNE94 93.945-93.955 93.900 22
4TNE98 97.945-97.955 97.900 22
4TNE106 (T) 105.930-l 05.960 105.880 30
if
the clearance between piston and cylinder exceeds the limit, use an oversized piston.
l
Oversized piston (0.25 mm)
I Code No.
1 Standard (mm) 1
I
4TNE94
1
129900-22700 I 694.250 I
I
4TNE98 129902-22700
I
$98.250
I
1 4TNE106 (
123900-22700
I
c$106.250
I
1 4TNE106T
/
123901-22700
I
$106.250
I
l
Cylinder boring dimension
/ Boring dimension (mm)
1
4TNE94 $94.250~$94.280
4TNE98 @98.250-698.280
4TNE106 (T) 1 @106.250-$106.280 1
Measure at positions a. b and c
in directions A and B.
a
b
c
Piston pin outside diameter
4-25