1995 JEEP YJ service

²The front and rear oil galley holes.
²The feed holes for the crankshaft main bearings.
Once the block has been completely cleaned, apply
Loctite PST pipe sealant with Teflon 592 to the
threads of the front and rear oil galley plugs. Tighten
the plugs to 41 Nzm (30 ft. lbs.) torque.
INSPECTIONÐCYLINDER BORE
(1) It is mandatory to use a dial bore gauge to
measure each cylinder bore diameter (Fig. 12). To
correctly select the proper size piston, a cylinder bore
gauge, Special Tool 6879, capable of reading in .00019
INCREMENTS is required. If a bore gauge is not
available, do not use an inside micrometer.
(2) Measure the inside diameter of the cylinder
bore at three levels below top of bore. Start perpen-
dicular (across or at 90 degrees) to the axis of the
crankshaft and then take two additional readings.
(3) Measure the cylinder bore diameter crosswise
to the cylinder block near the top of the bore. Repeat
the measurement near the middle of the bore, then
repeat the measurement near the bottom of the bore.
(4) Determine taper by subtracting the smaller di-
ameter from the larger diameter.
(5) Rotate measuring device 90É and repeat steps
above.
(6) Determine out-of-roundness by comparing the
difference between each measurement.
(7) If cylinder bore taper does not exceed 0.025 mm
(0.001 inch) and out-of-roundness does not exceed
0.025 mm (0.001 inch), the cylinder bore can be
honed. If the cylinder bore taper or out-of-round con-
dition exceeds these maximum limits, the cylinder
must be bored and then honed to accept an oversizepiston. A slight amount of taper always exists in the
cylinder bore after the engine has been in use for a
period of time.
HONINGÐCYLINDER BORE
The honing operation should be closely coordinated
with the fitting of pistons and rings. This will ensure
specified clearances are maintained.
Refer to Standard Service Procedures in the begin-
ning of this Group for the proper honing of cylinder
bores.
ASSEMBLY
Refer to the applicable sections for detailed instruc-
tions.
(1) Install the crankshaft.
(2) Install the connecting rods and the pistons
through the top of the cylinder bores.
(3) Install the oil pump.
(4) Install the oil pan and gasket.
(5) Install the camshaft.
(6) Install the sprockets and chain as an assembly.
(7) Install the oil slinger from the crankshaft.
(8) Install the timing case cover seal.
(9) Install the timing case cover.
(10) Install the vibration damper.
(11) Install the water pump. Tighten the mounting
bolts to 31 Nzm (270 in. lbs.) torque.
(12) Lubricate the oil filter seal with clean engine
oil. Tighten oil filter to 18 Nzm (13 ft. lbs.) torque.
(13) Install the engine into the vehicle.
(14) Fill the engine with clean lubrication oil (refer
to Group 0, Lubrication and Maintenance).
(15) Fill the cooling system (refer to Group 7, Cool-
ing System for the proper procedures).
Fig. 12 Cylinder Bore Measurement
9 - 92 4.0L ENGINEJ

EXHAUST SYSTEM AND INTAKE MANIFOLD
CONTENTS
page page
EXHAUST SYSTEM....................... 1
EXHAUST SYSTEM DIAGNOSIS............. 2SERVICE PROCEDURES................... 3
TORQUE SPECIFICATIONS................ 10
EXHAUST SYSTEM
GENERAL INFORMATION
The basic exhaust system consists of an engine ex-
haust manifold, exhaust pipe with oxygen sensor, cat-
alytic converter, exhaust heat shield(s), muffler and
exhaust tailpipe (Fig. 1).
The exhaust system uses a single muffler with a
single monolithic-type catalytic converter.
The 4.0L engines use a seal between the engine ex-
haust manifold and exhaust pipe to assure a tight
seal and strain free connections.
The exhaust system must be properly aligned to
prevent stress, leakage and body contact. If the sys-
tem contacts any body panel, it may amplify objec-tionable noises originating from the engine or body.
When inspecting an exhaust system, critically in-
spect for cracked or loose joints, stripped screw or
bolt threads, corrosion damage and worn, cracked or
broken hangers. Replace all components that are
badly corroded or damaged. DO NOT attempt to re-
pair.
When replacement is required, use original equip-
ment parts (or their equivalent). This will assure
proper alignment and provide acceptable exhaust
noise levels.
CAUTION: Avoid application of rust prevention com-
pounds or undercoating materials to exhaust sys-
tem floor pan exhaust heat shields. Light overspray
near the edges is permitted. Application of coating
will result in excessive floor pan temperatures and
objectionable fumes.
CATALYTIC CONVERTER
The stainless steel catalytic converter body is de-
signed to last the life of the vehicle. Excessive heat
can result in bulging or other distortion, but exces-
sive heat will not be the fault of the converter. If un-
burned fuel enters the converter, overheating may
occur. If a converter is heat-damaged, correct the
cause of the damage at the same time the converter
is replaced. Also, inspect all other components of the
exhaust system for heat damage.
Unleaded gasoline must be used to avoid contami-
nating the catalyst core.
EXHAUST HEAT SHIELDS
Exhaust heat shields are needed to protect both the
vehicle and the environment from the high tempera-
tures developed by the catalytic converter. The cata-
lytic converter releases additional heat into the
exhaust system. Under severe operating conditions,
the temperature increases in the area of the con-
Fig. 1 Typical Exhaust System
JEXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 1

SERVICE PROCEDURES
INDEX
page page
Catalytic Converter......................... 4
Engine Exhaust ManifoldÐ2.5L Engine.......... 7
Engine Exhaust ManifoldÐ4.0L Engine.......... 7
Exhaust PipeÐXJ Vehicles................... 3
Exhaust PipeÐYJ Vehicles................... 4Intake ManifoldÐ2.5L Engine................. 7
Intake ManifoldÐ4.0L Engine................. 8
Muffler and Exhaust TailpipeÐXJ Vehicles........ 5
Muffler and Exhaust TailpipeÐYJ Vehicles........ 6
EXHAUST PIPEÐXJ VEHICLES
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
REMOVAL
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve lu-
bricant (Fig. 1). Allow 5 minutes for penetration.
(3) Remove the oxygen sensor from the exhaust
pipe (Fig. 2).
(4) Disconnect the exhaust pipe from the engine
exhaust manifold. Discard the seal (4.0L engine,
only).(5) Support the transmission and remove the rear
crossmember.
(6) Remove the clamp nuts and clamp (Fig. 3). To
remove the exhaust pipe from the catalytic converter,
apply heat until the metal becomes cherry red. Dis-
connect the exhaust pipe from the catalytic converter
(Fig. 3). Remove the exhaust pipe.
Fig. 1 Exhaust Pipe-to-Engine Exhaust Manifold
Nuts
Fig. 2 Oxygen Sensor
Fig. 3 Exhaust Pipe-to-Catalytic Converter
Connection
JEXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 3

(2) Remove the clamp from the catalytic converter
and muffler connection (Fig. 6).
(3) Heat the catalytic converter and muffler con-
nection with an oxyacetylene torch until the metal
becomes cherry red.
(4) While the metal is still cherry red, twist the
muffler assembly back and forth to separate it from
the catalytic converter.
(5) Disconnect the exhaust pipe from the catalytic
converter (Figs. 3 and 5). If needed, heat up the pipes
to separate.
INSTALLATION
(1) Connect the catalytic converter to the exhaust
pipe (Figs. 3 and 5). Use a new clamp and tighten
the nuts to 61 Nzm (45 ft. lbs.) torque.
(2) Install the muffler onto the catalytic converter
until the alignment tab is inserted into the align-
ment slot.
(3) Install a new clamp at the muffler and catalytic
converter connection (Fig. 6). Tighten the clamp nuts
to 61 Nzm (45 ft. lbs.) torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
MUFFLER AND EXHAUST TAILPIPEÐXJ VEHICLES
All original equipment exhaust systems are manu-
factured with the exhaust tailpipe welded to the muf-
fler. Service replacement mufflers and exhaust
tailpipes are either clamped together or welded to-
gether.
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the front muffler clamp from the cata-
lytic converter and muffler connection (Fig. 6).
(3) Remove the rear exhaust tailpipe hanger clamp
(Fig. 7) and remove the exhaust tailpipe from the
front exhaust tailpipe hanger (Fig. 8).
(4) Heat the catalytic converter-to-muffler connec-
tion with an oxyacetylene torch until the metal be-
comes cherry red.
(5) While the metal is still cherry red, remove the
exhaust tailpipe/muffler assembly from the catalytic
converter.
(6) Remove the exhaust tailpipe from the muffler:
Fig. 6 Catalytic Converter-to-Muffler Connection
Fig. 7 Rear Exhaust Tailpipe Hanger Clamp
Fig. 8 Front Exhaust Tailpipe Hanger
JEXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 5

²To remove an original equipment exhaust tailpipe/
muffler combination, cut the exhaust tailpipe close to
the muffler. Collapse the part remaining in the muf-
fler and remove.
²To remove a service exhaust tailpipe/muffler com-
bination, apply heat until the metal becomes cherry
red. Remove the exhaust tailpipe/muffler clamp and
twist the exhaust tailpipe out of the muffler.
INSTALLATION
(1) Install the muffler onto the catalytic converter.
Install the clamp and tighten the nuts finger tight.
(2) Install the exhaust tailpipe into the rear of the
muffler.
(3) Install the exhaust tailpipe/muffler assembly on
the rear exhaust tailpipe hanger. Make sure that the
exhaust tailpipe has sufficient clearance from the
floor pan.
(4) Install the remaining clamps and the front ex-
haust tailpipe hanger.
(5) Tighten the nuts on the muffler-to-catalytic
converter clamp to 61 Nzm (45 ft. lbs.) torque (Fig. 6).
Tighten the nuts on the rear exhaust tailpipe clamp
to 14 Nzm (10 ft. lbs.) torque (Fig. 7).
(6) Lower the vehicle.
(7) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
MUFFLER AND EXHAUST TAILPIPEÐYJ VEHICLES
All original equipment exhaust systems are manu-
factured with the exhaust tailpipe welded to the muf-
fler. Service replacement mufflers and exhaust
tailpipes are clamped together.
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
REMOVAL
(1) Raise the vehicle and support the rear of the
vehicle by the side rails and allow the axle to hang
free.
(2) Remove the front muffler clamp from the cata-
lytic converter and muffler connection (Fig. 6).
(3) Remove the exhaust tailpipe hanger/bracket
(Fig. 9).
(4) Remove the exhaust tailpipe from the front ex-
haust tailpipe hanger (Fig. 10).
(5) Heat the converter-to-muffler connection with
an oxyacetylene torch until the metal becomes cherry
red.
(6) While the metal is still cherry red, place a
block of wood against the front of the muffler and
drive the muffler rearward to disengage.
(7) Remove the exhaust tailpipe/muffler assembly.
(8) Remove the exhaust tailpipe from the muffler:²To remove an original equipment exhaust tailpipe/
muffler combination, cut the exhaust tailpipe close to
the muffler. Collapse the part remaining in the muf-
fler and remove.
²To remove a service exhaust tailpipe/muffler com-
bination, remove the exhaust tailpipe/muffler clamp.
Heat the exhaust tailpipe-to-muffler connection with
an oxyacetylene torch until the metal becomes cherry
red. While the metal is still cherry red, twist the ex-
haust tailpipe out of the muffler.
Fig. 9 Rear Exhaust Tailpipe Hanger/Bracket
Fig. 10 Front Exhaust Tailpipe Hanger
11 - 6 EXHAUST SYSTEM AND INTAKE MANIFOLDJ

FUEL FILLER HOSE SPLASH SHIELDÐXJ
VEHICLES
REMOVAL
(1) Remove the screws that attach fuel filler hose
splash shield to wheelhouse panel and frame rail
(Fig. 7).
(2) Remove the hose splash shield from wheel-
house panel and frame rail (Fig. 7).
INSTALLATION
(1) Position fuel filler hose splash shield at wheel-
house panel and frame rail.
(2) Install screws to attach splash shield to wheel-
house panel and frame rail.
FUEL TANK SUPPORT STRAP
SERVICE INFORMATION
XJ fuel tank support straps are attached to the un-
derside of the vehicle via T-slots and hole-slots in the
frame members.
REMOVAL
(1) If equipped, position a support under skid
plate.
(2) If equipped, remove the bolts that attach skid
plate to underbody side rails.
(3) If applicable, remove the support and skid plate
from fuel tank.
(4) Support fuel tank.
(5) Loosen nut from fuel tank support strap bolt to
allow bolt head to be removed from hole-slot in frame
member (Fig. 8).
(6) Remove the strap T-end from frame member T-
slot (Fig. 9).
(7) Separate support strap from fuel tank and re-
move it from vehicle.
INSTALLATION
(1) Position support strap around fuel tank.
(2) Insert strap T-end in frame member T-slot.
(3) Insert bolt in hole-slot in frame member.
Tighten nut on the bolt until bolt-head and T-end are
seat and strap is tight against the bottom of fuel
tank.
(4) Remove the support from the fuel tank.
(5) If removed, position and support and the fuel
tank skid plate under the fuel tank.
(6) If applicable, install the bolts that attach the
skid plate to the underbody side rails. Tighten the
bolts to 50 Nzm (37 ft. lbs.) torque.
(7) Remove the support from under the skid plate.
Fig. 7 Fuel Filler Hose Splash ShieldÐXJ Vehicles
Fig. 8 Fuel Tank Support StrapÐXJ Vehicles
Fig. 9 Fuel Tank Support StrapsÐXJ Vehicles
13 - 4 XJÐFRAMEJ

BUMPERS
INDEX
page page
Front Bumper............................. 5
Front Tow Hooks........................... 7Rear Bumper............................. 8
Rear Tow Hook............................ 9
FRONT BUMPER
REMOVAL/DISASSEMBLY
(1) The bumper guards, end caps and tow hooks can
be removed from XJ front bumpers with the bumper at-
tached to the vehicle. Do not remove the bumper from
the vehicle if only these components require service.
If equipped with a brush guard, refer to the Brush
Guard Removal within Group 23, Body Components.(2) Disconnect the fog lamp wire harness connec-
tors, if equipped (Fig. 1).
(3) Disconnect the vacuum reservoir tube harness
connectors (Fig. 2 and 3).
(4) Remove the locknuts and Torx-head bolts that
attach the tow hook straps (Fig. 4) to the underbody
sillmember.
Fig. 1 Fog Lamp Wire Harness Connector
Fig. 2 Vacuum ReservoirÐLeft Side
Fig. 3 Vacuum ReservoirÐRight Side With Speed
Control Only
Fig. 4 Tow Hook & StrapÐXJ Vehicles
JXJÐBUMPERS 13 - 5

(12) Remove the fog lamps (Fig. 10) from the
bumper rail.
(13) If necessary, remove the vacuum reservoir(s)
from the bumper rail.
(14) If necessary, remove the sill crossmember re-
inforcement brackets from the sillmembers.
ASSEMBLY/INSTALLATION
(1) If removed, install the sill crossmember rein-
forcement brackets on the sillmembers (Fig. 11).
Tighten bolts to 56 Nzm (41 ft. lbs.) torque.
(2) If equipped, install the bumper support brack-
ets and bumper guards on the bumper rail. Tighten
hardware in the sequence indicated in (Fig. 6).
Tighten the locknuts with 20 Nzm (15 ft. lbs.) torque.
Tighten bolts to 56 Nzm (41 ft. lbs.) torque.
(3) If not equipped with bumper guards, install the
bumper support brackets on the bumper rail. Tighten
bolts to 56 Nzm (41 ft. lbs.) torque.
(4) Install tow hooks. Tighten nuts with 100 Nzm
(74 ft. lbs.) torque.
(5) Install the bumper end caps on the bumper
rail. Tighten nuts with 8 Nzm (72 in. lbs.) torque.(6) Install the license plate bracket on the bumper
rail. Tighten the nuts securely.
(7) Install the fog lamps on the bumper rail.
Tighten the nuts to 20 Nzm (15 ft. lbs.) torque.
(8) If removed, install the vacuum reservoir(s) on
the bumper rail. Tighten the retaining screws and
bolts to 8 Nzm (72 in. lbs.) torque.
(9) Position and support the bumper at the front of
the vehicle.
(10) Attach the bumper support brackets to the
right and left sillmembers and reinforcement brack-
ets. Tighten screws and bolts to 56 Nzm (41 ft. lbs.)
torque.
(11) Install the Torx-head bolts and locknuts that
attach the tow hook straps to the underbody sillmem-
ber. Tighten locknuts with 30 Nzm (22 ft. lbs.) torque.
Install the steering gear skid plate and screws
after the left tow hook strap has been installed.
(12) Connect the fog lamp wire harness connectors.
(13) Connect the vacuum reservoir tube harness
connectors.
(14) Remove the bumper support.
FRONT TOW HOOKS
If a tow hook must be replaced or removed only for
service access, remove the nuts and bolts that attach
it to the bumper support bracket. When installing a
tow hook, tighten nuts with 100 Nzm (74 ft. lbs.)
torque.
If a tow hook/bumper support bracket must be re-
placed, refer to the following removal and installation
procedures.
REMOVAL
If equipped with a brush guard, refer to the Brush
Guard Removal within Group 23, Body Components.
(1) Disconnect the fog lamp wire harness connec-
tors, if equipped.
(2) Disconnect the vacuum reservoir tube harness
connectors.
(3) Support the bumper.
(4) Remove the bolts that attach the bumper sup-
port brackets to the right and left sillmembers.
(5) Remove the locknuts and Torx-head bolts that
attach the tow hook straps to the underbody sillmem-
ber.
The retaining screws and the steering gear
skid plate must be removed before the left
strap can be removed from the sillmember.
(6) Detach the tow hook straps from the sillmem-
ber.
(7) Remove the support and the bumper from the
vehicle.
(8) Remove the nuts and bolts that attach the tow
hooks to the bumper support brackets.
(9) Remove the tow hook from the bumper support
bracket.
Fig. 10 Fog Lamp
Fig. 11 Reinforcement Brackets
JXJÐBUMPERS 13 - 7