CJ3A Operation and Care
Manual -- General Lubrication

The use of high grade lubricants and regular application is specially essential when operating the “Jeep” because of the diversified service it performs.  The amount of trouble free service received will be in proportion to the care given.  Lubricate the vehicle in accordance with the type of service performed.

The following pages should be referred to for instructions covering grade and quality of lubricant for all parts of the vehicle.  The mileage instructions should be followed when the vehicle is used for road work.  It is impossible to give accurate hourly instructions because of the diversified service and conditions under which the vehicle may be operated.  The hours indicated are approximate.  To obtain maximum service, good judgment must be used to lubricate the vehicle according to the type of work being done.  As an example – when used as a farm tractor under dusty conditions the chassis should be lubricated daily as the new lubrication forces grit and dirt, which has accumulated during the day, from the bearing surfaces.  Under these conditions, the air cleaner should also be cleaned and refilled daily or under extreme conditions twice daily.

Because of the importance of correct lubrication, detailed recommendations, unit capacities and specifications are given in the following paragraphs. Also see Fig. 17, LUBRICATION CHART

Above 90º F.................SAE 30
Not Lower than 32º F...SAE 20 or 30
As Low as +10º F........SAE 20 W
As Low as -10º F.........SAE 10 W
To temperatures below -10º F, use SAE 10 W plus 10% kerosene.
 

ENGINE LUBRICATION.
Lubrication of the engine is accomplished by means of a force-feed continuous circulating system.  This is effected by means of a gear type pump, located externally on the left side of the engine, and driven by a spiral gear on the camshaft.

The oil is drawn into the circulating system through a floating oil intake.  The floating intake does not permit water or dirt to circulate, which may hav accumulated in the bottom of the oil pan, because the oil is drawn horizontally from near the top surface.

An oil pressure gauge is mounted in the instrument panel, which indicates the pressure being supplied to the circulating system.  Failure of the gauge to register may indicate absence of oil, leakage or a fault in the lubrication system and the engine should be stopped immediately.  If there is plenty of oil in the reservoir the mechanical fault must be corrected before starting the engine.  Standard gauge reading is approximately 35 at 30 miles per hour and 10 at idle speed.

The quantity of the oil in the crankcase is measured by the bayonet type oil level indicator which is combined with the oil filler cap located in the oil filler pipe at the right side of the engine.  When the oil level is below the “Full” mark, pour sufficient new oil into the reservoir to bring the level to the “Full” mark.

When the vehicle leaves the factory the crankcase is filled to the correct level with oil of the proper viscosity for the “break-in” period.  When the vehicle is used on the highway, completely drain the engine oil at 500 miles and at 1000 miles, then every 2000 miles thereafter, by removing the drain plug in the lower left side of the oil pan.  Replace the drain plug and refill with 4 qts. (5 qts. when the engine oil filter has been drained) of fresh oil.  For heavy industrial or dusty field work, change the oil at the first 10 hours, and each 50 hours thereafter.  To secure maximum engine life, watch the condition of the oil closely and should it become contaminated, due to conditions under which the vehicle has been operated, change it immediately.

Always drain the oil when the engine is warm.  The benefit of draining is, to a large extent, lost if the crankcase is drained when the engine is cold, as some of the foreign matter will remain in the bottom of the oil pan.

At least once a year, preferably in the Spring, remove the oil pan and floating oil intake and wash thoroughly with cleaning solution.

CHASSIS LUBRICATION.
When lubricating the chassis refer to the Lubrication Chart.  For highway travel, clean and lubricate points 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 each 1000 miles.  When used in industrial or agricultural work the period for lubrication depends entirely upon the type of work being done.  When doing dusty field work, lubricate these points daily as grit and dirt will work into the bearing surfaces and cause rapid wear unless forced out by new lubricant.  The importance of using a good grade of chassis lubricant can not be exaggerated, for the cost will be more than repaid by longer wear and good service.

OIL FILTER.
The oil filter should be dismantled, cleaned and the filter element replaced at the end of the first 2000 miles of highway travel, or 100 hours of industrial or field use.  Drain the filter at each oil change to prevent the old oil contained in the filter from mixing with and contaminating the new oil.  Replace the element at each 8000 miles of highway use or 200 hours of industrial or field use.

AIR CLEANER.
Care of the air cleaner is EXTREMELY IMPORTANT – especially when the vehicle is used under dusty conditions.  Clean and refill the air cleaner reservoir to the level mark, with oil of the same grade used in the engine, at etch engine oil change.  When the vehicle is used for field work, clean and change the oil in the cleaner DAILY and under dusty conditions TWICE DAILY.  When cleaning, use a long screw driver or other suitable tool to dislodge dirt sticking to the bottom and sides of the intake passage in the body of the cleaner.

STEERING GEAR.
Check the level of the lubricant in the steering gear housing every 1000 miles.  Avoid the use of cup grease, graphite, white lead or heavy solidified oil.  Remove the plug in the steering gear housing and use a hand gun to fill the housing slowly.

WATER PUMP – CLUTCH.
The water pump and clutch release bearings are prelubricated at assembly and the lubricant lasts for the life of the bearings.

GENERATOR.
Two oilers are provided, one at each end; three to five drops of engine oil is recommended every 1000 miles.  Be sure to slip the commutator end hole cover back in place.

STARTING MOTOR.
The oil hole cover on the commutator (front) end slips to one side; put three to five drops of engine oil in this hole every 1000 miles.  Be sure to slip cover back in place.

IGNITION DISTRIBUTOR.
The oiler on the distributor should be lubricated every 1000 miles with several drops of engine oil, Fig. 7, No. 6.  Also place one drop of light engine oil on the wick, No. 2 located in the top of the shaft, which is accessible by removing the rotor arm and sparingly apply soft grease on the breaker arm cam No. 4, and a drop of oil on the breaker arm pivot, No. 3.  See PROPER MAINTENANCE for Fig. 7.

SPEEDOMETER AND DRIVE.
Some of the speedometers supplied are equipped with a wick type oiler located on the drive shaft boss directly above the tube and shaft connection to the speedometer head.  Lubricate this oiler with a few drops of light oil twice each year.  Remove the drive shaft from the tube once each year, clean it thoroughly and lubricate with a good quality light graphite grease.

UNIVERSAL JOINTS (PROPELLER SHAFT).
Every 1000 miles lubricate the propeller shaft universal joints and the slip joints with a good quality lubricant.  Lubricate daily for field work.

UNIVERSAL JOINTS (FRONT AXLE SHAFT).
The front axle universal joints are enclosed in the steering knuckle housings, which are filled with lubricant so require no attention other than checking each 1000 miles to be sure the housings are filled to plug level.  Once each year or every 300 hours of field work the axle shafts and universal joint assemblies should be removed, thoroughly cleaned and the housings filled with new lubricant.

WHEEL BEARINGS.
Front wheel bearings should be removed, thoroughly cleaned, checked and replaced twice yearly or every 6000 miles.  The rear wheel bearings are equipped with hydraulic lubricators.  Lubricate them sparingly to guard against surplus oil saturating the brake lining.  An oil relief hole at the top of housing, Fig. 32, No. 1, indicates when the bearing is filled with oil.

TRANMISSION AND TRANSFER CASE.
Drilled passages are provided between the transmission and transfer case housings for circulation of the lubricating oil to provide unit lubrication of the two assemblies.  The oil level should be checked each 1000 miles or at each lubrication.  Drain and refill at each 6000 miles or 300 hours of field work.

Note:  The requirements of these housings are small for economy, therefore, it is very important that the lubrication be changed every 300 hours when the vehicle is used for dusty field work.

FRONT AND REAR DIFFERENTIALS.
The differential gears require extreme pressure lubricant, which is suitable for hypoid gear type axles.  The level of the lubricant in these units should be checked every 1000 miles.  Do not mix different types of hypoid lubricants.  Drain and refill the housings each 6000 miles or twice yearly.  Use a light engine or flushing oil to clean out the housings.

Note:  Do not use water, steam, kerosene, or gasoline for flushing.  If the oil is decomposed, dismantling is necessary.

GOVERNOR.
At each lubrication, check the oil level in the governor housing.  Use oil of the same grade used in the engine to maintain the lubricant at filler plug level.  Drain and refill the housing at each 300 hours of operation.

POWER TAKE-OFF SHAFT AND PULLEY DRIVE HOUSINGS.
Check the lubricant level at each lubrication job, maintaining the lubricant at filler plug level.  Should the power take-off be used frequently, change the lubricant each 300 hours.

View Lubrication Chart.