1988 JEEP CHEROKEE ignition
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result in hard starting.
Fig. 2: Typical PCV Valve & Airflow
When engine is started, manifold vacuum pulls valve open
against spring pressure. As long as there is engine vacuum, the valve
floats, permitting crankcase fumes to enter intake manifold.
A baffle in rocker arm cover prevents oil from being drawn
into intake manifold through ventilator valve.
If the engine backfires, the ventilator valve will close.
This will prevent ignition of fumes in crankcase.
During certain engine operations, more blow-by is created
than ventilator valve can handle. Excess blow-by is returned to air
cleaner and carburetor through rocker arm cover and breather
assembly. It is then burned in the combustion chamber.
A breather assembly acts as separator to keep oil from being
drawn into air cleaner during this operation.
CCV SYSTEM
As stated above, the CCV system performs the same function
as a conventional PCV system, but does not use a vacuum controlled
valve.
A molded vacuum tube connects manifold vacuum to a grommet on
top of the cylinder head cover at the dash panel end. The grommet
contains a metered orifice of a calibrated size that meters the amount
of crankcase vapors drawn out of the engine. A fresh air supply hose
from the air cleaner is also connected to the front of the cylinder
head cover on 4.0L engines and to the rear of the cover on 2.5L
engines.
When the engine is operating, fresh air enters the engine
and mixes with crankcase vapors. Manifold vacuum draws the
vapor/air mixture through the metered orifice and into the intake
manifold. The vapors are consumed during combustion.
Page 951 of 1378
computers may lose memory data. When battery power is
restored, driveability problems may exist on some vehicles.
These vehicles may require a relearn procedure. See COMPUTER
RELEARN PROCEDURES article in GENERAL INFORMATION section.
REPLACING BLOWN FUSES
Before replacing a blown fuse, remove ignition key, turn off
all lights and accessories to avoid damaging the electrical system. Be
sure to use fuse with the correct indicated amperage rating. The use
of an incorrect amperage rating fuse may result in a dangerous
electrical system overload.
BRAKE PAD WEAR INDICATOR
Indicator will cause a squealing or scraping noise, warning
that brake pads need replacement.
BRAKE WARNING LIGHT
CAUTION: If BRAKE warning light is on with parking brake disengaged
and engine running, there may be a problem in the hydraulic
brake system. Braking effort, brake pedal travel and
stopping distances may increase.
CATALYTIC CONVERTER
To prevent catalytic converter overheating, DO NOT allow
engine to idle for more than 20 minutes.
COMMAND-TRAC (4WD)
CAUTION: NEVER operate a Command-Trac vehicle in 4WD on dry,
hard-surfaced roads for a sustained period. Use 4L only
when needed for added pulling power. Operating vehicle in
4WD mode on such roads will cause stress and possible
damage to components, as well as make shifting difficult.
To reduce shifting effort, drive vehicle in Reverse for a
few feet, or drive off hard-surfaced road momentarily to
allow tire slippage.
FRONT AND REAR DIFFERENTIALS (4WD)
CAUTION: DO NOT use water, steam, kerosene or gasoline for flushing
a differential. ONLY use a flushing oil.
TRAC-LOK DIFFERENTIALS (4WD)
CAUTION: DO NOT flush a rear axle Trac-Lok differential. Trac-Lok
differentials may be cleaned only by disassembling the
unit and wiping the components with clean, lint-free cloth.
CAUTION: NEVER attempt to engage Low range when vehicle is moving
faster than 2-3 MPH, as transfer case damage may result.
GASOLINE CONTAINING ALCOHOL
CAUTION: Exclusive use of gasohol is not recommended. Vehicle test
results have shown that significant fuel system corrosion
can result when gasohol is used exclusively.
Page 952 of 1378
HALOGEN BULBS
Halogen bulbs contain pressurized gas which may explode if
overheated. DO NOT touch glass portion of bulb with bare hands. Eye
protection should be worn when handling or working around halogen
bulbs.
OIL FILTER
CAUTION: The engine oil filter mount has metric threads. Use of a
filter with improper threads can result in oil leakage and
possible engine damage. Look for M20 x 1.5 symbol on the
filter.
RADIATOR CAP
CAUTION: Always disconnect the fan motor when working near the
radiator fan. The fan is temperature controlled and could
start at any time even when the ignition key is in the OFF
position. DO NOT loosen or remove radiator cap when cooling
system is hot.
RADIATOR FAN
Keep hands away from radiator fan. Fan is controlled by a
thermostatic switch which may come on or run for up to 15 minutes even
after engine is turned off.
WHEEL & TIRE WARNINGS
CAUTION: Replacing original tires with different size tires may
result in false speedometer and odometer indications. Check
with dealer before using different size tires on vehicle.
CAUTION: Ensure all 4 wheels on vehicle have same tire size, type
and circumference in order to provide proper vehicle
handling. DO NOT mix radial-ply with bias-ply or
bias-belted tires. On 4WD vehicles, if tire size, type and
circumference on all 4 wheels are not the same, gear
shifting will be adversely affected and can damage transfer
case.
CAUTION: Temporary-use spare tires are for emergency use only. DO
NOT drive vehicle faster than 50 MPH or more than 100 miles
when using spare tire. DO NOT operate vehicle in 4WD mode
when using spare tire, as damage to transfer case can
result. Temporary-use spare tires have a total tread life
of 3,000 miles.
SERVICE POINT LOCATIONS
Page 976 of 1378
Selec-Trac ................................. 3.0 Pts. (1.4L)
Command-Trac ............................... 2.2 Pts. (1.0L)
Drive Axles (
3)
Front ........................................ 2.5 Pts. (1.2L)
Front (Disconnect Housing) .................. 5.0 Ozs. (0.15L) \
Rear ......................................... 2.5 Pts. (1.2L)
Rear (Trac-Lok) (
4) .......................... 2.5 Pts. (1.2L)
(
1) - Capacities are recommended or calculated levels. Always use
dipstick (if available) to measure level.
(
2) - Includes 2.3 qts. for coolant recovery bottle.
(
3) - Fill to bottom of filler plug hole.
(
4) - Add 4 ozs. (118 ml) of Limited-Slip differential lubricant
additive first, then add new fluid.
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52,500 MILE (84,000 KM) SERVICE
52,500 MILE (84,000 KM) SERVICE \
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Service Or Inspect
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Verify Last Major Service Was Performed
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Check Fluid Levels
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Check Fuel Lines, Connections
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Check Cooling System Hoses and Clamps
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Check Exhaust System & Heat Shielding
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Curb & Fast Idle Speed
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Clean Choke Linkage
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Ignition Timing
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Inspect Brake System
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Inspect C/V Joint boots (4WD)
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Inspect Underside of Vehicle (Bolts & Threaded Fasteners)
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Check/Lube Manual Steering Gear
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Check Drive Shaft Seals
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Lubricate Ball Joints, Steering Linkage & Suspension
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Lube Drive Shaft U-Joints and Slip Splines
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Lube Front Axle Drive Joint and Pivot Bearings (4WD)
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Rotate Tires and Adjust Air Pressure (Including Spare)
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Replace
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Engine Oil
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Oil Filter, if it has not been changed in the last 12 months
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Choke Linkage
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Ignition Timing
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Lubricate Manifold Heat Control Valve (if equipped)
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Clean PCV Breather (if equipped)
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Clean EGR Passages (if equipped)
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Inspect C/V Joint boots (4WD)
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Inspect Underside of Vehicle (Bolts & Threaded Fasteners)
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Check/Lube Manual Steering Gear
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Check Drive Shaft Seals
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Lubricate Ball Joints, Steering Linkage & Suspension
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Lube Drive Shaft U-Joints and Slip Splines
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Lube Front Axle Drive Joint and Pivot Bearings (4WD)
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Inspect Front Wheel Bearings (4WD)
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Suspension Bushings, Springs, Arms & Rear Jounce Bumpers
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Parking Brake System
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Inspect Shocks for Leakage
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Inspect Tire Wear Pattern
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Rotate Tires and Adjust Air Pressure (Including Spare)
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Replace
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Engine Oil
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Oil Filter
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Spark Plugs
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Ignition Cables
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Distributor Cap and Rotor
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Air Filter Element
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EGR Valve & Tube (1987-92)
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Vacuum Operated Emission Components (1987-92)
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PCV Valve (
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Drive Belt (V-Type) (
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Flush and Fill Engine Coolant, if not done in last 24 months
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Automatic Transmission Fluid, Filter and Adjust Bands
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Accessory Drive Belts
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Fuel Filter](/manual-img/16/57037/w960_57037-979.png "JEEP CHEROKEE 1988 Service Repair Manual \b\
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Fuel Filter")
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Fuel Filter
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Emission System Vacuum Hoses
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Ignition Wires
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Distributor Cap & Rotor
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Battery
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(
1) - Replacement is recommended by Chrysler at this time, but it
is not required to maintain the warranty on the PCV valve.
(
2) - Check and replace as needed.
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Lubrication Specifications
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Application Specification
Automatic Transmission .......................... Dexron-IIE ATF
Brake Master Cylinder .......... DOT 3 (SAE J-1703F) Brake Fluid
Engine Coolant ........... Alugard 340-2 & Water (50/50 Mixture)
Engine Oil (
1)
Gasoline Engine
Temperature Range
Above 30
F (-1
C) ........ SAE 20W-40 Or 20W-50 API SH/CD
Above 0
F (-18
C) ......... SAE 10W-30 Or 10W-40 API SH/CD
Less Than 60
F (16
C) ............... SAE 5W-30 API SH/CD
Drive Axles ................................ SAE 75W-90 API GL-5
Drive Axles (Trac-Lok) (
2) ................ SAE 80W-140 API GL-5
Drive Axles (Trailer Towing) .............. SAE 80W-140 API GL-5
Hydraulic Clutch ............... DOT 3 (SAE J-1703F) Brake Fluid
Manual Transmission ........................ SAE 75W-90 API GL-5
Parking Brake Cable Guides ................. NLGI Grade 2, GC-LB
Door & Hood Hinges ............................ Light Engine Oil
Manual Steering Box ............... Multi-Purpose NLGI Grade 2EP
Power Steering Pump ....................... Power Steering Fluid
Transfer Case ................................... Dexron-IIE ATF
Brake Caliper Bushings ........ GE 661 or DOW 111 Silicone Grease
Caliper Slide Pins ........... GE 661 or DOW 111 Silicone Grease
Wheel Bearings .................. Multi-Purpose NLGI Grade GC-LB
Drive Shaft U-Joints .............. Multi-Purpose NLGI Grade 2EP
Steering Linkage (
4)( 5) .................... NLGI Grade 2, GC-LB
Ball Joints (
4)( 6) ......................... NLGI Grade 2, GC-LB
Weatherstrip .......................... Silicone Spray Lubricant
Wheel Lug Nut Torque ...................... 95 ft. lbs. (129 N.m)
(
1) - SAE 10W-30 SH/CD is preferred.
(
2) - Add 4 ozs. (118 ml) of Limited-Slip differential lubricant
additive when changing fluid.
(
3) - For vehicles operating under heavy-duty towing conditions,
use SAE 75W-140 Synthetic lube.
NOTE: Before using SAE 75W-140 Synthetic the old fluid must
be DRAINED and FLUSHED with clean mineral based axle
lubricant. Then refill with new synthetic lube.
(
4) - Use low pressure grease gun to prevent seal damage.
(
5) - Fill until lubricant squeezes out from the base of seals.
(
6) - Fill ball joint until seal starts to swell.
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Fluid Capacities
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Application ( 1) Quantity
Page 1000 of 1378
(1) - Capacities are recommended or calculated levels. Always use
dipstick (if available) to measure level.
(
2) - Includes 2.3 qts. for coolant recovery bottle.
(
3) - Fill to bottom of filler plug hole.
(
4) - Add 4 ozs. (118 ml) of Limited-Slip differential lubricant
additive first, then add new fluid.
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120,000 MILE (192,000 KM) SERVICE
120,000 MILE (192,000 KM) SERVICE \
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Service Or Inspect
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Verify Last Major Service Was Performed
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Check Fluid Levels
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Check Cooling System Hoses and Clamps
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Check Coolant Strength
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Check Accessory Drive Belts
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Check Exhaust System & Heat Shielding
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Clean Battery and Battery Terminals
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Adjust Drive Belt Tension
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Accessory Drive Belts
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Adjust Idle - Propane Method (1987-88)
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Ignition Timing
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Lubricate Manifold Heat Control Valve (3.9L & 5.2L Engines)
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Clean PCV Breather (3.9L & 5.2L Engines)
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Clean EGR Passages (if equipped)
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Inspect C/V Joint boots (4WD)
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Inspect Underside of Vehicle (Bolts & Threaded Fasteners)
\b\
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Check/Lube Manual Steering Gear
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Check Drive Shaft Seals
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Lubricate Ball Joints, Steering Linkage & Suspension
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Lube Drive Shaft U-Joints and Slip Splines
\b\
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Lube Front Axle Drive Joint and Pivot Bearings (4WD)
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Inspect Front Wheel Bearings (4WD)
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Clean and Lubricate Crankcase Inlet Air Cleaner
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Suspension Bushings, Springs, Arms & Rear Jounce Bumpers
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Page 1001 of 1378
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Parking Brake System
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Inspect Shocks for Leakage
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Inspect Tire Wear Pattern
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Rotate Tires and Adjust Air Pressure (Including Spare)
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Replace
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Engine Oil
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Oil Filter
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Spark Plugs
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Ignition Cables
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Distributor Cap and Rotor
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Air Filter Element
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Fuel Filter
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PCV Valve (
1)
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PCV Filter
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EGR Valve & Tube (1987-92)
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Vacuum Operated Emission Components (1987-92)
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PCV Valve (
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Drive Belt (V-Type) (
2)
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Flush and Fill Engine Coolant, if not done in last 24 months
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Automatic Transmission Fluid, Filter and Adjust Bands
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(
1) - Replacement is recommended by Chrysler at this time, but it
is not required to maintain the warranty on the PCV valve.
(
2) - Check and replace as needed.
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Lubrication Specifications
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Application Specification
Automatic Transmission .......................... Dexron-IIE ATF
Brake Master Cylinder .......... DOT 3 (SAE J-1703F) Brake Fluid
Engine Coolant ........... Alugard 340-2 & Water (50/50 Mixture)
Engine Oil (
1)
Gasoline Engine
Temperature Range
Above 30
F (-1
C) ........ SAE 20W-40 Or 20W-50 API SH/CD
Above 0
F (-18
C) ......... SAE 10W-30 Or 10W-40 API SH/CD
Less Than 60
F (16
C) ............... SAE 5W-30 API SH/CD
Drive Axles ................................ SAE 75W-90 API GL-5
Drive Axles (Trac-Lok) (
2) ................ SAE 80W-140 API GL-5
Drive Axles (Trailer Towing) .............. SAE 80W-140 API GL-5
Hydraulic Clutch ............... DOT 3 (SAE J-1703F) Brake Fluid
Manual Transmission ........................ SAE 75W-90 API GL-5
Parking Brake Cable Guides ................. NLGI Grade 2, GC-LB