Jeep Wrangler TJ. Manual — part 430
(3) Examine block and cylinder bores for cracks or
fractures.
(4) Check block deck surfaces for flatness. Deck
surface must be within service limit of 0.1 mm (0.004
in.).
CYLINDER BORE
NOTE: The cylinder bores should be measured at
normal room temperature, 21°C (70°F).
The cylinder walls should be checked for out-of-
round and taper with Tool C119 or equivalent (Fig.
39) (Refer to 9 - ENGINE - SPECIFICATIONS). If
the cylinder walls are badly scuffed or scored, the
cylinder block should be replaced, and new pistons
and rings fitted.
Measure the cylinder bore at three levels in direc-
tions A and B (Fig. 39). Top measurement should be
10 mm (3/8 in.) down and bottom measurement
should be 10 mm (3/8 in.) up from bottom of bore.
(Refer to 9 - ENGINE - SPECIFICATIONS).
CONNECTING ROD BEARINGS
STANDARD PROCEDURE
CONNECTING ROD - FITTING
(1) For measuring connecting rod bearing clear-
ance procedure and use of Plastigage (Refer to 9 -
ENGINE - STANDARD PROCEDURE). For bearing
clearance refer to Engine Specifications. (Refer to 9 -
ENGINE - SPECIFICATIONS)
NOTE: The rod bearing bolts should not be reused.
(2) Before installing the NEW bolts the threads
should be oiled with clean engine oil.
(3) Install each bolt finger tight then alternately
torque each bolt to assemble the cap properly.
(4) Tighten the bolts to 27 N·m PLUS 1/4 turn (20
ft. lbs. PLUS 1/4 turn) Do not use a torque
wrench for last step.
(5) Using a feeler gauge, check connecting rod side
clearance (Fig. 40). Refer to clearance specifications
(Refer to 9 - ENGINE - SPECIFICATIONS).
Fig. 39 Checking Cylinder Bore Size
Fig. 40 Connecting Rod Side Clearance
TJ
ENGINE 2.4L
9 - 35
ENGINE BLOCK (Continued)
CRANKSHAFT
DESCRIPTION
The crankshaft is made of nodular cast iron and
includes five main bearing journals and four connect-
ing rod journals (Fig. 41). The number three journal
is the location for the thrust bearing. The mains and
connecting rod journals have undercut fillet radiuses
that are rolled for added strength. To optimize bear-
ing loading, eight counterweights are used.
OPERATION
The crankshaft transfers force generated by com-
bustion within the cylinder to the flywheel or flex-
plate.
STANDARD PROCEDURE - CRANKSHAFT END
PLAY
(1) Using Dial Indicator C-3339 and Mounting
Post L-4438, attach to front of engine, locating probe
perpendicular on nose of crankshaft (Fig. 42).
(2) Move crankshaft all the way to the rear of its
travel.
(3) Zero the dial indicator.
(4) Move crankshaft all the way to the front and
read the dial indicator. Refer to Engine Specifica-
tions.
REMOVAL
NOTE: Crankshaft can not be removed when engine
is in vehicle.
(1) Remove engine assembly from vehicle. (Refer to
9 - ENGINE - REMOVAL)
(2) Remove flex plate and crankshaft rear oil seal.
(3) Mount engine on a repair stand.
(4) Drain engine oil and remove oil filter.
(5) Remove the oil pan. (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL)
(6) Remove the timing belt covers. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)
(7) Remove the timing belt. (Refer to 9 - ENGINE/
VALVE
TIMING/TIMING
BELT/CHAIN
AND
SPROCKETS - REMOVAL)
(8) Remove the oil pump. (Refer to 9 - ENGINE/
LUBRICATION/OIL PUMP - REMOVAL)
(9) Remove balance shafts and housing assembly.
(Refer to 9 - ENGINE/VALVE TIMING/BALANCE
SHAFT - REMOVAL)
(10) Using a permanent ink or paint marker, iden-
tify cylinder number on each connecting rod cap (Fig.
43).
CAUTION: DO NOT use a number stamp or a punch
to mark connecting rods. Damage to connecting
rod could occur.
Fig. 41 Crankshaft - Typical
1 - MAIN BEARING JOURNALS
2 - COUNTER BALANCE WEIGHTS
Fig. 42 CHECKING CRANKSHAFT END PLAY
Fig. 43 Identify Connecting Rod to Cylinder-Typical
9 - 36
ENGINE 2.4L
TJ
(11) Remove all connecting rod bolts and caps.
Care should be taken not to damage the fracture rod
and cap surfaces.
NOTE: Do not reuse connecting rod bolts.
(12) Remove all bedplate bolts from the engine
block (Fig. 44).
(13) Using a mallet gently tap the bedplate loose
from the engine block dowel pins.
CAUTION: Do not pry up on one side of the bed-
plate. Damage may occur to cylinder block to bed-
plate alignment and thrust bearing.
(14) Bedplate should be removed evenly from the
cylinder block dowel pins to prevent damage to the
dowel pins and thrust bearing.
(15) Lift out crankshaft from cylinder block. Do
not damage the main bearings or journals when
removing the crankshaft.
(16) Remove the target ring mounting screws and
discard.
(17) Remove the target ring from the crankshaft.
INSPECTION
The crankshaft journals should be checked for
excessive wear, taper and scoring (Fig. 45). Limits of
taper or out of round on any crankshaft journals
should within specitifications. (Refer to 9 - ENGINE -
SPECIFICATIONS)
Journal
grinding
should
not
exceed 0.305 mm (0.012 in.) under the standard jour-
nal diameter. DO NOT grind thrust faces of No. 3
main bearing. DO NOT nick crank pin or bearing fil-
lets. After grinding, remove rough edges from crank-
shaft oil holes and clean out all passages.
CAUTION: With the nodular cast iron crankshafts, it
is important that the final paper or cloth polish be
in the same direction as normal rotation in the
engine.
INSTALLATION
(1) Install the main bearing shells with the lubri-
cation groove in the cylinder block (Fig. 46).
(2) Make certain oil holes in block line up with oil
hole in bearings and bearing tabs seat in the block
tab slots.
CAUTION: Do not get oil on the bedplate mating
surface. It will affect the sealer ability to seal the
bedplate to cylinder block.
NOTE: If the crankshaft is sent out for machine
work, it must be balenced as an assembly with the
target ring installed.
(3) Clean
crankshaft
and
target
ring
with
MOPAR
t brake parts cleaner and dry with com-
Fig. 44 Bedplate Bolt Tightening Sequence
Fig. 45 Crankshaft Journal Measurements
Fig. 46 Installing Main Bearing Upper Shell
1 - LUBRICATION GROOVES
2 - OIL HOLES
TJ
ENGINE 2.4L
9 - 37
CRANKSHAFT (Continued)
pressed air to ensure that the crankshaft mating sur-
face and target ring mounting holes are free from oil
and lock patch debris.
NOTE: Always use NEW mounting screws whether
installing original or new target ring.
(4) Install NEW mounting screws finger tight
starting with the #1 location. (Fig. 47) Make sure
engagment occurs with the shoulder of the screw and
mounting hole before starting all other screws.
(5) Torque all mounting screws with T30 torx bit
to 13 Nm (110 in-lbs) following the torque sequence.
CAUTION: Use extreme care when handling crank-
shaft. Tone wheel damage can occur if crankshaft is
mis-handled.
(6) Oil the bearings and journals. Install crank-
shaft.
CAUTION: Use only the specified anaerobic sealer
on the bedplate or damage may occur to the
engine.
(7) Apply 1.5 to 2.0 mm (0.059 to 0.078 in.) bead of
Mopar
t Bed Plate Sealant to cylinder block as shown
in (Fig. 48).
(8) Install lower main bearings into main bearing
cap/bedplate. Make certain the bearing tabs are
seated into the bedplate slots. Install the main bear-
ing/bedplate into engine block.
(9) Before installing the bolts the threads should
be oiled with clean engine oil, wipe off any excess oil.
(10) Install main bearing bedplate to engine block
bolts 11, 17, and 20 finger tight. Tighten these bolts
down together until the bedplate contacts the cylin-
der block.
(11) To ensure correct thrust bearing alignment,
perform the following steps:
• Step 1: Rotate crankshaft until number 4 piston
is at TDC.
• Step 2: Move crankshaft rearward to limits of
travel.
• Step 3: Then, move crankshaft forward to limits
of travel.
• Step 4: Wedge an appropriate tool between the
rear of the cylinder block (NOT BED PLATE) and
the rear crankshaft counterweight. This will hold the
crankshaft in it’s furthest forward position.
• Step 5: Install and tighten bolts (1–10) in
sequence shown in (Fig. 49) to 41 N·m (30 ft. lbs.).
• Step 6: Remove wedge tool used to hold crank-
shaft.
(12) Tighten bolts (1–10) again to 41 N·m (30 ft.
lbs.) +1/4 turn in sequence shown in (Fig. 49).
Fig. 47 Target Ring Torque Sequence
Fig. 48 Bedplate Sealing
Fig. 49 Bedplate Bolt Torque Sequence
9 - 38
ENGINE 2.4L
TJ
CRANKSHAFT (Continued)
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