Komatsu 4D98 Series Shop Manual page 61

4.
Engine Body
Point 6
Disassemble:
. Install a bolt as a handle in the hole at the end face of the flywheel and remove carefully so
as
not to damage the ring gear.
Reassemble:
Flywheel mounting bolt T = 186.3-2059Nm (19-21 kgf-m), apply lube oil
Point 7
Disassemble:
l
Measure the camshaft side gap.
(mm)
l
If the measured side gap exceeds the
limit, replace the thrust metal.
Disassemble:
Since the camshaft gear is shrink-fit,
heat it to 180 "C-200 "C for extraction.
Camshaft side
gap
J
For camshaft removal, raise the engine with its mounting flange at the bottom. After remov-
ing the thrust metal mounting bolt from the camshaft gear hole, extract the camshaft care-
fully so as not to damage the bearing bushing.
Rotate the camshaft a few turns before extracting it to prevent the tappet from being caught
by the cam.
After removing the camshaft, set the engine horizontal and fix it on the base.
Unforeseen injury may arise due to falling of slipping when raising the engine
vertically or returning it to the horizontal position. Proceed carefully so as not to
lose balance.
Point 8
Reassemble:
l
Do not forget to install the oil pan mounting bolts on the bottom side when installing the gear
case.
l
Apply sealant (code No. 977770-01212)and install the gear case by matching the two dowel
pins.
Point 9
Reassemble:
l
Replace the oil seal whenever disassembled.
l
Apply lithium grease at the time of assembly.
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