Mitsubishi Montero (1991+). Manual - part 113

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

         Ensure cylinder is checked for taper, out-of-round and

properly honed prior to checking piston and cylinder bore fit. See

CYLINDER BLOCK in this article. Using dial bore gauge, measure

cylinder bore. Measure piston at right angle to piston pin in center

of piston skirt area. Subtract piston diameter from cylinder bore

diameter. The difference is piston-to-cylinder clearance. Clearance

must be within specification. Mark piston for proper cylinder

location.

         ASSEMBLING PISTON & CONNECTING ROD

         Install proper fitted piston on connecting rod for proper

cylinder. Ensure piston marking on top of piston marked is in

correspondence with connecting rod and cap number. See  Fig. 14.

Fig. 14:  Piston Pin Installation - Typical

This Graphic For General Information Only

         Lubricate piston pin and install in connecting rod. Ensure

piston pin retainers are fully seated (if equipped). On pressed type

piston pins, follow manufacturer’s recommended procedure to avoid

distortion or breakage.

         CHECKING PISTON RING CLEARANCES

         Piston rings must be checked for side clearance and end gap.

To check end gap, install piston ring in cylinder which it is to be

installed. Using an inverted piston, push ring to bottom of cylinder

in smallest cylinder diameter.

         Using feeler gauge, check ring end gap. See  Fig. 15. Piston

ring end gap must be within specification. Ring breakage will occur

with insufficient ring end gap.

         On some manufacturers, insufficient ring end gap may be

corrected by using a fine file while other manufacturers recommend

using another ring set. Mark rings for proper cylinder installation

after checking end gap.

Fig. 15:  Checking Piston Ring End Gap - Typical

This Graphic For General Information Only

         For checking side clearance, install rings on piston. Using

feeler gauge, measure clearance between piston ring and piston ring

land. Check side clearance in several areas around piston. Side

clearance must be within specification.

         If side clearance is excessive, piston ring grooves can be

machined to accept oversized piston rings (if available). Normal

practice is to replace piston.