BEARINGS-CRANKSHAFT MAIN
STANDARD PROCEDURE
MAIN BEARING FITTING
SELECT FIT IDENTIFICATION
The main bearings are “select fit” to achieve proper oil
clearances. For main bearing selection, the crankshaft
position sensor target wheel (2) has grade identifica-
tion marks stamped into it. These marks are read from
left to right, corresponding with journal number 1, 2, 3,
4. The crankshaft position sensor target wheel is
mounted to the number 6 counter weight (1) on the
crankshaft.
INSPECTION
Wipe the inserts clean and inspect for abnormal wear patterns and for metalor other foreign material imbedded in
the lining. Normal main bearing insert wear patterns are illustrated.
Inspect the back of the inserts for fractures, scrapings or irregular wearpatterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
MAIN BEARING JOURNAL DIAMETER (CRANKSHAFT REMOVED)
Remove the crankshaft from the cylinder block (Refer to 9 - ENGINE/ENGINE BLOCK/CRANKSHAFT - REMOVAL).
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal with a micrometer. Measure at two locations 90° apart at each end
of the journal.
The maximum allowable taper is 0.008mm (0.0004 inch.) and maximum out of round is 0.005mm (0.002 inch). Com-
pare the measured diameter with the journal diameter specification (MainBearing Fitting Chart). Select inserts
required to obtain the specified bearing-to-journal clearance.
Install the crankshaft into the cylinder block (Refer to 9 - ENGINE/ENGINEBLOCK/CRANKSHAFT - INSPECTION).
Check crankshaft end play.
CRANKSHAFT MAIN BEARING SELECTION
SEAL-CRANKSHAFT OIL-REAR
DIAGNOSIS AND TESTING - REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in therear seal area of the engine, a more
involved inspection is necessary. The following steps should be followedto help pinpoint the source of the leak.
If the leakage occurs at the crankshaft rear oil seal area:
1. Disconnect the battery.
2. Raise the vehicle.
3. Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light
to check for the oil leak:
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
b. Where leakage tends to run straight down, possible causes are a porous block, oil galley pipe plugs, oil filter
runoff, and main bearing cap to cylinder block mating surfaces. See Engine, for proper repair procedures of
these items.
4. If no leaks are detected, pressurized the crankcase as outlined in the section, Inspection (Engine oil Leaks in
general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
5. If the leak is not detected, very slowly turn the crankshaft and watch forleakage. If a leak is detected between
the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged.
The seal area on the crankshaft could have minor nicks or scratches that canbe polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks or
scratches. The crankshaft seal flange is specially machined to complement the function of the rear oil seal.
6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled. (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING), under the Oil Leak row, for components inspections on possible
causes and corrections.
7. After the oil leak root cause and appropriate corrective action have been identified, (Refer to 9 - ENGINE/EN-
GINE BLOCK/CRANKSHAFT OIL SEAL - REAR - REMOVAL).
REMOVAL
NOTE: This procedure can be performed in vehi-
cle.
1. If being performed in vehicle, remove the transmis-
sion.
2. Remove the flexplate (Refer to 9 - ENGINE/EN-
GINE BLOCK/FLEX PLATE - REMOVAL).
NOTE: The crankshaft oil seal CAN NOT be reused
after removal.
NOTE: The crankshaft rear oil seal remover Spe-
cial Tool 8506 must be installed deeply into the
seal. Continue to tighten the removal tool into the
seal until the tool can not be turned farther. Fail-
ure to install tool correctly the first time will cause
tool to pull free of seal without removing seal from
engine.
3. Using Special Tool 8506 (2), remove the crankshaft rear oil seal (1)
REMOVAL
1. Disconnect negative cable from battery.
2. Remove the following components:
Oil pan and gasket/windage tray (Refer to 9 - ENGINE/LUBRICATION/OIL PAN -REMOVAL).
Cylinder head covers (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL) and
(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
Timing chain cover (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) - REMOVAL).
Cylinder head(s) (Refer to 9 - ENGINE/CYLINDER HEAD - REMOVAL) and (Refer to 9 - ENGINE/CYLINDER
HEAD - REMOVAL).
3. If necessary, remove top ridge of cylinder bores with a reliable ridge reamer before removing pistons from cyl-
inder block.Be sure to keep tops of pistons covered during this operation.Pistons and connecting rods
must be removed from top of cylinder block. When removing piston and connecting rod assemblies from the
engine, rotate crankshaft so the each connecting rod is centered in cylinder bore.
CAUTION: DO NOT use a number stamp or a punch to mark connecting rods or caps,as damage to con-
necting rods could occur
NOTE: Connecting rods and bearing caps are not interchangeable and shouldbe marked before removing
to ensure correct reassembly.
4. Mark connecting rod and bearing cap positions using a permanent ink marker or scribe tool.
CAUTION: Care must be taken not to damage the fractured rod and cap joint face surfaces, as engine dam-
age may occur.
5. Remove connecting rod cap. Install Special Tool 8507 Connecting Rod Guides into the connecting rod being
removed. Remove piston from cylinder bore. Repeat this procedure for eachpiston being removed.
CAUTION: Care must be taken not to nick crankshaft journals, as engine damage may occur
6. Immediately after piston and connecting rod removal, install bearing cap on the mating connecting rod to prevent
damage to the fractured cap and rod surfaces.
CLEANING
CAUTION: DO NOT use a wire wheel or other abrasive cleaning devise to clean the pistons or connecting
rods. The pistons have a Moly coating, this coating must not be damaged.
1. Using a suitable cleaning solvent clean the pistons in warm water and towel dry.
2. Use a wood or plastic scraper to clean the ring land grooves.
CAUTION: DO NOT remove the piston pin from the piston and connecting rod assembly.
INSPECTION
Check the connecting rod journal for excessive wear, taper and scoring (Refer to 9 - ENGINE/ENGINE BLOCK/
CONNECTING ROD BEARINGS - STANDARD PROCEDURE).
Check the connecting rod for signs of twist or bending.
Check the piston for taper and elliptical shape before it is fitted into thecylinder bore (Refer to 9 - ENGINE/ENGINE
BLOCK/PISTON & CONNECTING ROD - STANDARD PROCEDURE).
Check the piston for scoring, or scraping marks in the piston skirts. Checkthe ring lands for cracks and/or deteri-
oration.
RINGS-PISTON
STANDARD PROCEDURE - PISTON RING FITTING
Before reinstalling used rings or installing new rings,
the ring clearances must be checked.
1. Wipe the cylinder bore clean.
2. Insert the ring in the cylinder bore.
NOTE: The ring gap measurement must be made
with the ring positioned at least 12mm (0.50 inch.)
from bottom of cylinder bore.
3. Using a piston, to ensure that the ring is squared in
the cylinder bore, slide the ring downward into the
cylinder.
4. Using a feeler gauge (1) check the ring end gap.
Replace any rings not within specification.
PISTON RING SIDE CLEARANCE
NOTE: Make sure the piston ring grooves are
clean and free of nicks and burrs.
5. Measure the ring side clearance as shown make sure the feeler gauge (1) fits snugly between the ring land and
the ring. Replace any ring not within specification.
6. Rotate the ring around the piston, the ring must rotate in the groove without binding.
PISTON RING SPECIFICATION CHART
Ring Position Groove Clearance Maximum Clearance
Upper Ring .051-.094 mm 0.11 mm
(0.0020-.0037 in.) (0.004 in.)
Intermediate Ring 0.04-0.08 mm 0.10 mm
(0.0016-0.0031 in.) (0.004 in.)
Oil Control Ring .019-.229 mm .25 mm
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the engine, particularly at thearea of the suspected leak. If an oil leak
source is not readily identifiable, thefollowingstepsshouldbefollowed:
1. Do not clean or degrease the engine at this time because some solvents maycause rubber to swell, temporarily
stopping the leak.
2. Add an oil soluble dye (use as recommended by manufacturer). Start the engine and let idle for approximately 15
minutes. Check the oil dipstick to make sure the dye is thoroughly mixed as indicated with a bright yellow color
under a black light.
3. Using a black light, inspect the entire engine for fluorescent dye, particularly at the suspected area of oil leak. If
the oil leak is found and identified, repair per service manual instructions.
4. If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspec-
tion.If the oil leak source is not positively identified at this time, proceed with the air leak detection test method.
Air Leak Detection Test Method
1. Disconnect the breather cap to air cleaner hose at the breather cap end. Cap or plug breather cap nipple.
2. Remove the PCV valve from the cylinder head cover. Cap or plug the PCV valvegrommet.
3. Attach an air hose with pressure gauge and regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to more than 20.6 kPa (3 PSI) of test pressure.
4. Gradually apply air pressure from 1 psi to 2.5 psi maximum while applyingsoapy water at the suspected source.
Adjust the regulator to the suitable test pressure that provide the best bubbles which will pinpoint the leak
source. If the oil leak is detected and identified, repair per service manual procedures.
5. If the leakage occurs at the rear oil seal area, refer to the section, Inspection for Rear Seal Area Leak.
6. If no leaks are detected, turn off the air supply and remove the air hose and all plugs and caps. Install the PCV
valve and breather cap hose.
7. Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various speeds approx-
imately 24 km (15 miles). Inspect the engine for signs of an oil leak by usinga black light.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in therear seal area of the engine, a more
involved inspection is necessary. The following steps should be followedto help pinpoint the source of the leak.
If the leakage occurs at the crankshaft rear oil seal area:
1. Disconnect the battery.
2. Raise the vehicle.
3. Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light
to check for the oil leak:
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
b. Where leakage tends to run straight down, possible causes are a porous block, oil galley pipe plugs, oil filter
runoff, and main bearing cap to cylinder block mating surfaces.
4. If no leaks are detected, pressurize the crankcase as outlined in the, Inspection (Engine oil Leaks in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
5. If the leak is not detected, very slowly turn the crankshaft and watch forleakage. If a leak is detected between
the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged.
The seal area on the crankshaft could have minor nicks or scratches that canbe polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially machined to complement the function of the rear oil seal.
6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled.
DIAGNOSIS AND TESTING - CHECKING ENGINE OIL PRESSURE
1. Remove oil pressure sending unit (2) and install
gauge assembly C-3292.
2. Run engine until thermostat opens.
3. Oil Pressure:
Curb Idle - 25 kPa (4 psi) minimum
3000 rpm - 170 - 758 kPa (25 - 110 psi)
4. If oil pressure is 0 at idle, shut off engine. Check
for a clogged oil pick-up screen or a pressure relief
valve stuck open.
DIAGNOSIS AND TESTING - REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in therear seal area of the engine, a more
involved inspection is necessary. The following steps should be followedto help pinpoint the source of the leak.
If the leakage occurs at the crankshaft rear oil seal area:
1. Disconnect the battery.
2. Raise the vehicle.
3. Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light
to check for the oil leak:
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
b. Where leakage tends to run straight down, possible causes are a porous block, oil galley pipe plugs, oil filter
runoff, and main bearing cap to cylinder block mating surfaces. See Engine, for proper repair procedures of
these items.
4. If no leaks are detected, pressurized the crankcase as outlined in the section, Inspection (Engine oil Leaks in
general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
5. If the leak is not detected, very slowly turn the crankshaft and watch forleakage. If a leak is detected between
the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged.
The seal area on the crankshaft could have minor nicks or scratches that canbe polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks or
scratches. The crankshaft seal flange is specially machined to complement the function of the rear oil seal.
6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled. (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING), under the Oil Leak row, for components inspections on possible
causes and corrections.
7. After the oil leak root cause and appropriate corrective action have been identified, (Refer to 9 - ENGINE/EN-
GINE BLOCK/CRANKSHAFT OIL SEAL - REAR - REMOVAL).
REMOVAL
1. Disconnect the negative battery cable.
2. Install engine support fixture special tool # 8534.
Do not raise engine at this time.
3. Loosen both left and right side engine mount
through bolts. Do not remove bolts.
4. Remove the structural dust cover, if equipped.
5. Drain engine oil.
6. Remove the front crossmember (Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - REMOVAL).
CAUTION: Only raise the engine enough to pro-
vide clearance for oil pan removal. Check for
proper clearance at fan shroud to fan and cowl to
intake manifold.
7. Raise engine using special tool 8534 to provide
clearance to remove oil pan.
NOTE:Donotpryonoilpanoroilpangasket.
Gasket is integral to engine windage tray and does
not come out with oil pan.
8. Remove the oil pan mounting bolts and oil pan (1).
9. Unbolt oil pump pickup tube and remove tube.
10. Inspect the integral windage tray and gasket (2)
and replace as needed.
1. If removed, install stud at position No. 9.
2. Position the oil pan and install the mounting bolts
and nut. Tighten the mounting bolts and nut to 15
Nꞏm (11 ft. lbs.) in the sequence shown .
3. Lower the engine into mounts using special tool
8534.
4. Install both the left and right side engine mount
through bolts. Tighten the nuts to 68 Nꞏm (50 ft.
lbs.).
5. Remove special tool 8534.
6. Install structural dust cover, if equipped.
7. Install the front crossmember (Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - INSTALLATION).
8. Fill engine oil.
9. Reconnect the negative battery cable.
10. Start engine and check for leaks.