Engine And Components; R&R Engine; Cylinder Head; Compression Release - Kubota L185 Shop Manual

SHOP MANUAL
Paragraphs 22-24
ENGINE AND COMPONENTS
R&R ENGINE
All Models
22. To remove engine and clutch as a
unit, first drain cooling system, engine
oil, transmission oil, power steering
reservoir (if equipped) and front wheel
drive differential housing (if equipped).
Remove front axle assembly as follows:
Remove hood, side panels and upper
support rail (if equipped), muffler and
battery. Disconnect radiator hoses and
air cleaner hose. Disconnect drag link
end using a suitable puller. On front
wheel drive models, unbolt and remove
drive shaft. On all models, support
tractor under clutch housing and sup-
port front end unit with a suitable hoist
or splitting stand. Remove front axle
bracket mounting cap screws, then roll
front end away from engine. To
separate engine from clutch housing,
disconnect wiring to engine as necessary
Disconnect fuel supply line, fuel return
line and hydraulic hoses and tubes.
Disconnect throttle control linkage,
engine stop rod (if equipped), hour-
meter cable and decompression cable.
Support engine with a suitable hoist,
remove cap screws securing flywheel
housing to clutch housing and separate
engine from transmission.
To reinstall engine, reverse the
removal procedure. Tighten clutch hous-
ing mounting cap screws to a torque of
49-54 N-m (36-41 ft.-lbs.). Tighten front
axle bracket fasteners to the following
torques: MIO nut to 61-71 N-m (45-50
ft.-lbs.), MIO bolt to 48-56 N-m (;-i6-41
ft.-lbs.) and M12 nut or bolt ot 78-90
N-m (58-66 ft.-lbs.).
CYLINDER HEAD
All Models
23. To remove cylinder head, first
drain cooling system and disconnect bat-
tery cables. Remove hood, muffler and
side covers (if equipped). Remove upper
radiator hose, coolant return hose and
intake manifold hose. Disconnect decom-
pressor control cable. Remove injection
lines and nozzle assemblies and cap all
exposed fittings to prevent entry of dirt.
Remove alternator adjusting bracket.
Remove valve lever cover. Remove
valve levers an(i shaft assembly and
withdraw push ro(is. Remove cap screws
and nuts securing cylinder head and lift
head off cylinder block.
One or more shims may he installed
between gasket and cylinder head to ad-
just clearance between cylinder head
and piston tops. Identify shims when
cylinder head is removed, then install an
equal number of shims when head is
reinstalled. To check piston to head
clearance, insert a soft lead wire
through injection nozzle holder hole.
Rotate crankshaft by hand until lead
wire is fiattened by piston top. Measure
thickness of fiattened wire to determine
top clearance which should be 0.7-0.9
mm (0.028-0.035 inch).
NOTE: Because of minimum amount of
clearance that exists between vaives and
piston tops, ioosen vaive iever adjusting
screws before reinstailing vaive ievers
and shaft assembiy to prevent possibie
damage to vaives.
Check cylinder head surface for
distortion using a straightedge and
feeler gage. If a 0.05 mm (0.002 inch)
feeler gage can be inserted between
cylinder head and straightedge, head
surface should be refaced with a surface
grinder. A maximum of 0.5 mm (0.020
inch) of material may be removed to true
cylinder head surface. Refer to
paragraph 25 for valve head recession
specifications.
When installing cylinder head, use
new head gasket and install shims (if us-
ed) between gasket and cylinder head.
Be sure sealing surfaces are clean and
dry. Apply light coat of engine oil to
threads of retaining nuts and cap
screws. Tightening torque on all models
is 73.5-78.4 N-m (55-58 ft.-lbs.). On all
models, tighten nuts and cap screws
evenly in three stages using recommend-
ed sequence shown in Fig. 45.
Adjust valve clearance as outlined in
paragraph 25 and compression release
mechanism as outlined in paragraph 24.
Retorque cylinder head cap screws and
nuts after running engine for approx-
imately 30 minutes using proper tighten-
ing sequence.
COMPRESSION RELEASE
All Models
24. Compression release mechanism
is contained within valve lever cover.
When decompressor knob is pulled,
decompressor shaft rotates allowing ad-
justing screws to contact exhaust valve
levers. The decompressor screws will
hold exhaust valves slightly open, reduc-
ing compression resistance when start-
ing engine, until decompressor knob is
returned to normal operating position.
To adjust compression release,
remove adjusting covers from valve
lever cover (Fig. 46). Pull decompressor
knob out, then turn crankshaft by hand
until exhaust valve being adjusted is
completely closed (piston at TDC com-
pression stroke). Turn decompressor
screw down until it contacts valve lever.
Flywheel side
Fig. 45—When tightening
cyiinder head boits, use ap-
propriate sequence shown
for two, three or four cylinder
engines.
Bolt
Nut
19