Disassembly Of Engine; Disassembly Of Camshaft And Timing - Yanmar 4TNV98 Service Manual

Disassembly of Engine

Prepare a clean, flat working surface on a
workbench large enough to accommodate the
engine components. Discard all used gaskets, O-
rings and seals. Use new gaskets, O-rings and seals
on reassembly of engine.
CAUTION
Identify all parts and their location using an
appropriate method. It is important that all parts
are returned to the same position during the
reassembly process.
If the engine will be completely disassembled, the
following preliminary steps should be performed:
1. Disconnect the battery cables at the battery.
Always disconnect the negative (-) cable first.
2. Remove the throttle cable, electrical connections,
intake and exhaust system connections, and fuel
supply lines from the engine.
3. Remove the alternator.
4. Drain the engine coolant from the radiator and
cylinder block. See Drain, Flush and Refill Cooling
System With New Coolant on page 159. Remove
the cooling system components from the engine.
5. Remove the engine from the machine. Mount the
engine to a suitable engine repair stand having
adequate weight capacity.
Be sure to secure the engine solidly to prevent
injury or damage to parts due to the engine
falling during work on the engine.
6. Clean the engine by washing with solvent, air or
steam cleaning. Carefully operate so as to prevent
any foreign matter or fluids from entering the
engine or any fuel system or electrical
components remaining on the engine.
7. Drain the engine oil into a suitable container.
Remove the oil filter.
8. Remove the cylinder head. See 4-Valve Cylinder
4TNV98 & 4TNE98 Diesel Engine
CAUTION
Head on page 80.
9. Remove the fuel injection pump from the gear
case / front plate only if it must be sent out for
repair, or will interfere with other procedures such
as "hot tank" cleaning. If the fuel injection pump
does not need to be repaired, leaving it mounted
to the timing gear case or plate will eliminate the
need to re-time it during reassembly. See Fuel
Injection Pump on page 141.
10. Remove the starter motor. See Removal of
Starter Motor on page 225.

Disassembly of Camshaft and Timing

Components
Discard all gaskets, O-rings and seals. Use new
gaskets, O-rings and seals on reassembly of the
camshaft and timing components.
Removal of Timing Gear Case Cover
1. Remove the bolt and washer retaining the
crankshaft pulley.
Use care not to damage the threads in the end of
the crankshaft when removing the crankshaft pulley.
2. Remove the crankshaft pulley using a gear puller.
3. Remove the bolts that retain the gear case cover
to the cylinder block and oil pan.
4. Remove the gear case cover (Figure 6-85, (1)).
111
IMPORTANT
Section 3. Engine