Mitsubishi Montero (1998+). Manual - part 145

NOTE:    Always refer to appropriate engine overhaul article in the

         ENGINES section for complete overhaul procedures and

         specifications for the vehicle being repaired.

         CLEANING & INSPECTION

         Clean camshaft with solvent. Ensure all oil passages are

clear. Inspect cam lobes and bearing journals for pitting, flaking or

scoring. Using micrometer, measure bearing journal O.D.

         Support camshaft at each end with "V" blocks. Position dial

indicator with tip resting on center bearing journal. Rotate camshaft

and note reading. If reading exceeds specification, replace camshaft.

         Check cam lobe lift by measuring base circle of camshaft

using micrometer. Measure again at 90 degrees to tip of cam lobe. Cam

lift can be determined by subtracting base circle diameter from tip of

cam lobe measurement.

         Different lift dimensions are given for intake and exhaust

cam lobes. Reading must be within specifications. Replace camshaft if

cam lobes or bearing journals are not within specifications.

         Inspect camshaft gear for chipped, eroded or damaged teeth.

Replace gear if damaged. On camshafts using thrust plate, measure

distance between thrust plate and camshaft shoulder. Replace thrust

plate if not within specification.

         CAMSHAFT BEARINGS

         Removal & Installation

         Remove the camshaft rear plug. The camshaft bearing remover

is assembled with its shoulder resting on the bearing to be removed

according to manufacturer’s instructions. Tighten puller nut until

bearing is removed. Remove remaining bearings, leaving front and rear

bearings until last. These bearings act as guide for camshaft bearing

remover.

         To install new bearings, puller is rearranged to pull

bearings toward the center of block. Ensure all lubrication passages

of bearing are aligned with cylinder block. Coat new camshaft rear

plug with sealant. Install camshaft rear plug. Ensure plug is even

in cylinder block.

         CAMSHAFT INSTALLATION

         Lubricate bearing surfaces and cam lobes with ample amount of

Molykote or camshaft lubricant. Carefully install camshaft. Use care

not to damage bearing journals during installation. Install thrust

plate retaining bolts (if equipped). Tighten bolts to specification.

On overhead camshafts, install bearing caps in original location.

Tighten bolts to specification. Check end play.

         CAMSHAFT END PLAY

         Using dial indicator, check end play. Position dial indicator

on front of engine block. Position indicator tip against camshaft.

Push camshaft toward rear of engine and adjust indicator to zero.

         Move camshaft forward and note reading. Camshaft end play

must be within specification. End play may be adjusted by relocating

gear, shimming thrust plate or replacing thrust plate depending on

manufacturer.

         TIMING CHAINS & BELTS

         * 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.

         TIMING CHAINS

         Timing chains will stretch during operation. Limits are

placed upon amount of stretch before replacement is required. Timing

chain stretch will alter ignition timing and valve timing.

         To check timing chain stretch, rotate crankshaft to eliminate

slack from one side of timing chain. Mark reference point on cylinder

block. Rotate crankshaft in opposite direction to eliminate slack from

remaining side of timing chain. Force other side of chain outward

and measure distance between reference point and timing chain. See

Fig. 23. Replace timing chain and gears if not within specification.

Fig. 23:  Measuring Timing Chain Stretch - Typical

This Graphic For General Information Only

         Timing chains must be installed so that timing marks on

camshaft gear and crankshaft gear are aligned according to

manufacturer. See Fig. 24.

Fig. 24:  Timing Gear Mark Alignment - Typical

This Graphic For General Information Only

         TIMING BELTS

         Cogged tooth belts are commonly used on overhead cam

engines. Inspect belt teeth for rounded corners or cracking. Replace

belt if cracked, damaged, missing teeth or oil soaked.

         Used timing belt must be installed in original direction of

rotation. Inspect all sprocket teeth for wear. Replace all worn

sprockets. Sprockets are marked for timing purposes. Engine is

positioned so that crankshaft sprocket mark will be upward. Camshaft

sprocket is aligned with reference mark on cylinder head and timing

belt is installed. See Fig. 25.

Fig. 25:  Timing Belt Sprocket Alignment - Typical

This Graphic For General Information Only

         TENSION ADJUSTMENTS

         If guide rails are used with spring loaded tensioners,

ensure at least half of original rail thickness remains. Spring

loaded tensioner should be inspected for damage.

         Ensure all timing marks are aligned. Adjust belt tension

using manufacturer’s recommendations. Belt tension may require

checking using tension gauge. See Fig. 26.