bolts MITSUBISHI MONTERO 1998 Workshop Manual

NOTE: Always refer to appropriate engine overhaul article in the
ENGINES section for complete overhaul procedures and
specifications for the vehicle being repaired.
REMOVAL
Remove intake and exhaust manifolds and valve cover. Cylinder
head and camshaft carrier bolts (if equipped), should be removed only
when the engine is cold. On many aluminum cylinder heads, removal
while hot will cause cylinder head warpage. Mark rocker arm or
overhead cam components for location.
Remove rocker arm components or overhead cam components.
Components must be installed in original location. Individual design
rocker arms may utilize shafts, ball-type pedestal mounts or no rocker
arms. For all design types, wire components together and identify
according to the corresponding valve. Remove cylinder head bolts.
Note length and location. Some applications require cylinder head
bolts be removed in proper sequence to prevent cylinder head damage.
See Fig. 1 . Remove cylinder head.
Fig. 1: Typical Cylinder Head Tightening or Loosening Sequence
This Graphic For General Information Only
INSTALLATION
Ensure all surfaces and head bolts are clean. Check that head
bolt holes of cylinder block are clean and dry to prevent block damage
when bolts are tightened. Clean threads with tap to ensure accurate
bolt torque.
Install head gasket on cylinder block. Some manufacturer's
may recommend sealant be applied to head gasket prior to installation.
Note that all holes are aligned. Some gasket applications may be
marked so certain area faces upward. Install cylinder head using care
not to damage head gasket. Ensure cylinder head is fully seated on
cylinder block.
Some applications require head bolts be coated with sealant
prior to installation. This is done if head bolts are exposed to water
passages. Some applications require head bolts be coated with light
coat of engine oil.

Install head bolts. Head bolts should be tightened in proper
steps and sequence to specification. See Fig. 1. Install remaining
components. Tighten all bolts to specification. Adjust valves if
required. See VALVE ADJUSTMENT in this article.
NOTE: Some manufacturers require that head bolts be retightened
after specified amount of operation. This must be done to
prevent head gasket failure.
VALVE ADJUSTMENT
Engine specifications will indicate valve train clearance and
temperature at which adjustment is to be made on most models. In most
cases, adjustment will be made with a cold engine. In some cases, both
a cold and a hot clearance will be given for maintenance convenience.
On some models, adjustment is not required. Rocker arms are
tightened to specification and valve lash is automatically set. On
some models with push rod actuated valve train, adjustment is made at
push rod end of rocker arm while other models do not require
adjustment.
Clearance will be checked between tip of rocker arm and tip
of valve stem in proper sequence using a feeler gauge. Adjustment is
made by rotating adjusting screw until proper clearance is obtained.
Lock nut is then tightened. Engine will be rotated to obtain all valve
adjustments to manufacturer's specifications.
Some models require hydraulic lifter to be bled down and
clearance measured. Different length push rods can be used to obtain
proper clearance. Clearance will be checked between tip of rocker arm
and tip of valve stem in proper sequence using a feeler gauge.
On overhead cam engines designed without rocker arms actuate
valves directly on a cam follower. A hardened, removable disc is
installed between the cam lobe and lifter. Clearance will be checked
between cam heel and adjusting disc in proper sequence using a feeler
gauge. Engine will be rotated to obtain all valve adjustments.
On overhead cam engines designed with rocker arms, adjustment
is made at push rod end of rocker arm. Ensure that the valve to be
adjusted is riding on the heel of the cam on all engines. Clearance
will be checked between tip of rocker arm and tip of valve stem in
proper sequence using a feeler gauge. Adjustment is made by rotating
adjusting screw until proper clearance is obtained. Lock nut is then
tightened. Engine will be rotated to obtain all valve adjustments to
manufacturer's specifications.
CYLINDER HEAD OVERHAUL
* PLEASE READ THIS FIRST *
NOTE: Always refer to appropriate engine overhaul article in the
ENGINES section for complete overhaul procedures and
specifications for the vehicle being repaired.
DISASSEMBLY
Mark valves for location. Using valve spring compressor,
compress valve springs. Remove valve locks. Carefully release spring
compressor. Remove retainer or rotator, valve spring, spring seat and
valve. See Fig. 2.

than .010" (.25 mm) from tip. Chamfer sharp edge of reground valve
tip. Recheck valve stem installed height.
VALVE STEM OIL SEALS
Valve stem oil seals must be installed on valve stem. See
Fig. 2 . Seals are needed due to pressure differential at the ends of
valve guides. Atmospheric pressure above intake guide, combined with
manifold vacuum below guide, causes oil to be drawn into the cylinder.
Exhaust guides also have pressure differential created by
exhaust gas flowing past the guide, creating a low pressure area. This
low pressure area draws oil into the exhaust system.
Replacement (On Vehicle)
Mark rocker arm or overhead cam components for location.
Remove rocker arm components or overhead cam components. Components
must be installed in original location. Remove spark plugs. Valve stem
oil seals may be replaced by holding valves against seats using air
pressure.
Air pressure must be installed in cylinder using an adapter
for spark plug hole. An adapter can be constructed by welding air hose
connection to spark plug body with porcelain removed.
Install adapter in spark plug hole. Apply a minimum of 140
psi (9.8 kg/cm
) to adapter. Air pressure should hold valve closed. If
air pressure does not hold valve closed, check for damaged or bent
valve. Cylinder head must be removed for service.
Using valve spring compressor, compress valve springs. Remove
valve locks. Carefully release spring compressor. Remove retainer or
rotator and valve spring. Remove valve stem oil seal.
If oversized valves have been installed, oversized oil seals
must be used. Coat valve stem with engine oil. Install protective
sleeve over end of valve stem. Install new oil seal over valve stem
and seat on valve guide. Remove protective sleeve. Install spring
seat, valve spring and retainer or rotator. Compress spring and
install valve locks. Remove spring compressor. Ensure valve locks
are fully seated.
Install rocker arms or overhead cam components. Tighten all
bolts to specification. Adjust valves if required. Remove adapter.
Install spark plugs, valve cover and gasket.
VALVE SPRING INSTALLED HEIGHT
Valve spring installed height should be checked during
reassembly. Measure height from lower edge of valve spring to the
upper edge. DO NOT include valve spring seat or retainer. Distance
must be within specifications. If valves and/or seats have been
ground, a valve spring shim may be required to correct spring height.
See Fig. 12 .
Fig. 12: Measuring Valve Spring Installed Height - Typical
This Graphic For General Information Only

ROCKER ARMS & ASSEMBLIES
Rocker Studs
Rocker studs are either threaded or pressed in place.
Threaded studs are removed by locking 2 nuts on the stud. Unscrew the
stud by turning the jam nut. Coat the stud threads with Loctite and
install. Tighten to specification.
Pressed in stud can be removed using a stud puller. Ream the
stud bore to proper specification and press in a new oversize stud.
Pressed in studs are often replaced by cutting threads in the stud
bore to accept a threaded stud.
Rocker Arms & Shafts
Mark rocker arms for location. Remove rocker arm retaining
bolts. Remove rocker arms. Inspect rocker arms, shafts, bushings and
pivot balls (if equipped) for excessive wear. Inspect rocker arms
for wear in valve stem contact area. Measure rocker arm bushing I.D.
Replace bushings if excessively worn.
The rocker arm valve stem contact point can be reground,
using special fixture for valve grinding machine. Remove minimum
amount of material as possible. Ensure all oil passages are clear.
Install rocker arms in original locations. Ensure rocker arm is
properly seated in push rod. Tighten bolts to specification. Adjust
valves if required. See VALVE ADJUSTMENT in this article.
Pushrods
Remove rocker arms. Mark push rods for location. Remove push
rods. Push rods can be steel or aluminum, solid or hollow. Hollow
pushrods must be internally cleaned to ensure oil passage to the
rocker arms is cleaned. Check the pushrod for damage, such as loose
ends on steel tipped aluminum types.
Check push rod for straightness. Roll push rod on a flat
surface. Using feeler gauge, check clearance at center. Replace push
rod if bent. The push rod can also be supported at each end and
rotated. A dial indicator is used to detect bends in the push rod.
Lubricate ends of push rod and install push rod in original
location. Ensure push rod is properly seated in lifter. Install rocker
arm. Tighten bolts to specification. Adjust valves if required. See
VALVE ADJUSTMENT in this article.
LIFTERS
Hydraulic Lifters
Before replacing a hydraulic lifter for noisy operation,
ensure noise is not caused by worn rocker arms or valve tips.
Hydraulic lifter assemblies must be installed in original locations.
Remove the rocker arm assembly and push rod. Mark components for
location. Some applications require intake manifold, or lifter cover
removal. Remove lifter retainer plate (if used). To remove lifters,
use a hydraulic lifter remover or magnet. Different type lifters are
used. See Fig. 13.

interchangeable. Inspect all components for wear. Note amount of wear
in lifter body-to-camshaft contact area. Surface must have smooth and
convex contact face. If wear is apparent, carefully inspect cam lobe.
Inspect push rod contact area and lifter body for scoring
or signs of wear. If body is scored, inspect lifter bore for damage
and lack of lubrication. On roller type lifters, inspect roller for
flaking, pitting, loss of needle bearings and roughness during
rotation.
Measure lifter body O.D. in several areas. Measure lifter
bore I.D. of cylinder block. Some models offer oversized lifters.
Replace lifter if damaged.
If lifter check valve is not operating, obstructions may be
preventing it from closing or valve spring may be broken. Clean or
replace components as necessary.
Check plunger operation. Plunger should drop to bottom of the
body by its own weight when assembled dry. If plunger is not free,
soak lifter in solvent to dissolve deposits.
Lifter leak-down test can be performed on lifter. Lifter
must be filled with special test oil. New lifters contain special test
oil. Using lifter leak-down tester, perform leak-down test following
manufacturer's instructions. If leak-down time is not within
specifications, replace lifter assembly.
Lifters should be soaked in clean engine oil several hours
prior to installation. Coat lifter base, roller (if equipped) and
lifter body with ample amount of Molykote or camshaft lubricant. See
Fig. 13. Install lifter in original location. Install remaining
components. Valve lash adjustment is not required on most hydraulic
lifters. Preload of hydraulic lifter is automatic. Some models may
require adjustment.
Mechanical Lifters
Lifter assemblies must be installed in original locations.
Remove rocker arm assembly and push rod. Mark components for location.
Some applications require intake manifold or lifter cover removal.
Remove lifter retainer plate (if used). To remove lifters, use lifter
remover or magnet.
Inspect push rod contact area and lifter body for scoring or
signs of wear. If body is scored, inspect lifter bore for damage and
lack of lubrication. Note amount of wear in lifter body-to-camshaft
contact area. Surface must have smooth and convex contact face. If
wear is apparent, carefully inspect cam lobe.
Coat lifter base, roller (if equipped) and lifter body with
ample amount of Molykote or camshaft lubricant. Install lifter in
original location. Install remaining components. Tighten bolts to
specification. Adjust valves. See VALVE ADJUSTMENT in this article.
PISTONS, CONNECTING RODS & BEARINGS
* PLEASE READ THIS FIRST *
NOTE: Always refer to appropriate engine overhaul article in the
ENGINES section for complete overhaul procedures and
specifications for the vehicle being repaired.
RIDGE REMOVAL
Ridge in cylinder wall must be removed prior to piston
removal. Failure to remove ridge prior to removing pistons will cause
piston damage in piston ring locations.
With the piston at bottom dead center, place a rag in the
bore to trap metal chips. Install ridge reamer in cylinder bore.
Adjust ridge reamer using manufacturer's instructions. Remove ridge

using ridge reamer. DO NOT remove an excessive amount of material.
Ensure ridge is completely removed.
PISTON & CONNECTING ROD REMOVAL
Note top of piston. Some pistons may contain a notch, arrow
or be marked "FRONT". Piston must be installed in proper direction to
prevent damage with valve operation.
Check that connecting rod and cap are numbered for cylinder
location and which side of cylinder block the number faces. Proper cap
and connecting rod must be installed together. Connecting rod cap must
be installed on connecting rod in proper direction to ensure bearing
lock procedure. Mark connecting rod and cap if necessary. Pistons must
be installed in original location.
Remove cap retaining nuts or bolts. Remove bearing cap.
Install stud protectors on connecting rod bolts. This protects
cylinder walls from scoring during removal. Ensure proper removal of
ridge. Push piston and connecting rod from cylinder. Connecting rod
boss can be tapped with a wooden dowel or hammer handle to aid in
removal.
PISTON & CONNECTING ROD
Disassembly
Using ring expander, remove piston rings. Remove piston pin
retaining rings (if equipped). On pressed type piston pins, special
fixtures and procedures according to manufacturer must be used to
remove piston pins. Follow manufacturer's recommendations to avoid
piston distortion or breakage.
Cleaning
Remove all carbon and varnish from piston. Pistons and
connecting rods may be cleaned in cold type chemical tank. Using ring
groove cleaner, clean all deposits from ring grooves. Ensure all
deposits are cleaned from ring grooves to prevent ring breakage or
sticking. DO NOT attempt to clean pistons using wire brush.
Inspection
Inspect pistons for nicks, scoring, cracks or damage in ring
areas. Connecting rod should be checked for cracks using Magnaflux
procedure. Piston diameter must be measured in manufacturers specified
area.
Using telescopic gauge and micrometer, measure piston pin
bore of piston in 2 areas, 90 degrees apart. This is done to check
diameter and out-of-round.
Install proper bearing cap on connecting rod. Ensure bearing
cap is installed in proper location. Tighten bolts or nuts to
specification. Using inside micrometer, measure inside diameter in 2
areas, 90 degrees apart.
Connecting rod I.D. and out-of-round must be within
specification. Measure piston pin bore I.D. and piston pin O.D. All
components must be within specification. Subtract piston pin diameter
from piston pin bore in piston and connecting rod to determine proper
fit.
Connecting rod length must be measured from center of
crankshaft journal inside diameter to center of piston pin bushing
using proper caliper. Connecting rods must be the same length.
Connecting rods should be checked on an alignment fixture for bent or
twisted condition. Replace all components which are damaged or not
within specification.
PISTON & CYLINDER BORE FIT

over connecting rod bolts. Install piston and connecting rod assembly.
Ensure piston notch, arrow or "FRONT" mark is toward front of engine.
See Fig. 17 .
Fig. 17: Installing Piston & Connecting Rod Assembly - Typical
This Graphic For General Information Only
Carefully tap piston into cylinder until rod bearing is
seated on crankshaft journal. Remove protectors. Install rod cap and
bearing. Lightly tighten connecting rod bolts. Repeat procedure for
remaining cylinders. Check bearing clearance. See
MAIN & CONNECTING ROD BEARING CLEARANCE in this article.
Once clearance is checked, lubricate journals and bearings.
Install bearing caps. Ensure marks are aligned on connecting rod and
cap. Tighten rod nuts or bolts to specification. Ensure rod moves
freely on crankshaft. Check connecting rod side clearance. See
CONNECTING ROD SIDE CLEARANCE in this article.
CONNECTING ROD SIDE CLEARANCE
Position connecting rod toward one side of crankshaft as far
as possible. Using feeler gauge, measure clearance between side of
connecting rod and crankshaft. See Fig. 18. Clearance must be within
specifications.

Fig. 18: Measuring Connecting Rod Side Clearance - Typical
This Graphic For General Information Only
Check for improper bearing installation, wrong bearing cap
or insufficient bearing clearance if side clearance is insufficient.
Connecting rod may require machining to obtain proper clearance.
Excessive clearance usually indicates excessive wear at crankshaft.
Crankshaft must be repaired or replaced.
MAIN & CONNECTING ROD BEARING CLEARANCE
Plastigage Method
Plastigage method may be used to determine bearing clearance.
Plastigage can be used with an engine in service or during reassembly.
Plastigage material is oil soluble.
Ensure journals and bearings are free of oil or solvent.
Oil or solvent will dissolve material and false reading will be
obtained. Install small piece of Plastigage along full length of
bearing journal. Install bearing cap in original location. Tighten
bolts to specification.
CAUTION: DO NOT rotate crankshaft while Plastigage is installed.
Bearing clearance will not be obtained if crankshaft is
rotated.
Remove bearing cap. Compare Plastigage width with scale on
Plastigage container to determine bearing clearance. See Fig. 19.
Rotate crankshaft 90 degrees. Repeat procedure. this is done to check
journal eccentricity. This procedure can be used to check oil
clearance on both connecting rod and main bearings.

Fig. 19: Measuring Bearing Clearance - Typical
This Graphic For General Information Only
Micrometer & Telescopic Gauge Method
A micrometer is used to determine journal diameter, taper and
out-of-round dimensions of the crankshaft. See CLEANING & INSPECTION
under CRANKSHAFT & MAIN BEARINGS in this article.
With crankshaft removed, install bearings and caps in
original location on cylinder block. Tighten bolts to specification.
On connecting rods, install bearings and caps on connecting rods.
Install proper connecting rod cap on corresponding rod. Ensure bearing
cap is installed in original location. Tighten bolts to specification.
Using a telescopic gauge and micrometer or inside micrometer
measure inside diameter of connecting rod and main bearings bores.
Subtract each crankshaft journal diameter from the corresponding
inside bore diameter. This is the bearing clearance.

CRANKSHAFT & MAIN BEARINGS
* PLEASE READ THIS FIRST *
NOTE: Always refer to appropriate engine overhaul article in the
ENGINES section for complete overhaul procedures and
specifications for the vehicle being repaired.
REMOVAL
Ensure all main bearing caps are marked for location on
cylinder block. Some main bearing caps have an arrow stamped on it
which must face front of engine. Remove main bearing cap bolts. Remove
main bearing caps. Carefully remove crankshaft. Use care not to bind
crankshaft in cylinder block during removal.
CLEANING & INSPECTION
Thoroughly clean crankshaft using solvent. Dry with
compressed air. Ensure all oil passages are clear and free of sludge,
rust, dirt, and metal chips.
Inspect crankshaft for scoring and nicks. Inspect crankshaft
for cracks using Magnaflux procedure. Inspect rear seal area for
grooving or damage. Inspect bolt hole threads for damage. If pilot
bearing or bushing is used, check pilot bearing or bushing fit in
crankshaft. Inspect crankshaft gear for damaged or cracked teeth.
Replace gear if damaged. Check that oil passage plugs are tight (if
equipped).
Using micrometer, measure all journals in 4 areas to
determine journal taper, out-of-round and undersize. See Fig. 20.
Some crankshafts can be reground to the next largest undersize,
depending on the amount of wear or damage. Crankshafts with rolled
fillet cannot be reground and must be replaced.
Fig. 20: Measuring Crankshaft Journal - Typical
This Graphic For General Information Only
Crankshaft journal runout should be checked. Install
crankshaft in "V" blocks or bench center. Position dial indicator