Jeep CJ/Scrambler 1971-1986 Repair Guide




See Figures 1 and 2

Make sure that your vehicle is on a level surface to ensure an accurate reading. Then, raise the hood, position the holdup rod, and measure the oil with the dipstick which is on the left side of 4-cylinder and V8 engines and on the right of 6-cylinder engines. Add oil through the filler pipe on the right side of 4-134 engines. Add oil through the valve cover filler hole on 4-150, 4-151, 6-225, 6-232 and 6-258, and through the filler pipe at the front of the engine on V8s.

If the oil is below the ADD mark, add a quart of oil, then recheck the level. If the level is still not reading full, add only a half of a quart at a time, until the dipstick reads FULL. Do not overfill the engine. When you check the oil, make sure that you allow sufficient time for all of the oil to drain back into the crankcase after stopping the engine. A minute or so should be enough time.

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Fig. Fig. 1: Remove the dipstick from the engine

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Fig. Fig. 2: Check the oil level on the dipstick, it should be at the full mark


See Figures 3, 4, 5 and 6

The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize your exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

The engine oil is to be changed every 4,000 miles. The oil should be changed more frequently, however, under conditions such as:

Driving in dusty conditions
Continuous trailer pulling or RV use
Extensive or prolonged idling
Extensive short trip operation in freezing temperatures (when the engine is not thoroughly warmed up)
Frequent long runs at high speeds and high ambient temperatures
Stop-and-go service, such as delivery trucks,

The oil change interval and filter replacement interval should be cut in half. Operation of the engine in severe conditions, such as a dust storm, volcanic ash or deep water, may require an immediate oil and filter change.

Before draining the oil, make sure that the engine is at operating temperature. Hot oil will hold more impurities in suspension and will flow better, removing more oil and dirt.

Drain the oil into a suitable receptacle. Waste oil may be disposed of at a garage or service facility which accepts waste oil for recycling.

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Fig. Fig. 3: Remove the oil drain plug using an 3/4 in. wrench

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Fig. Fig. 4: Apply a clean coat of oil to the oil filter gasket before installing it

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Fig. Fig. 5: Fill the engine with the correct amount of oil, be sure to check the dipstick

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Fig. Fig. 6: Oil filter mounting on the inline 6 cylinder engine

After the drain plug is loosened, unscrew the plug with your fingers, using a rag to shield your fingers from the heat. Push in on the plug as you unscrew it so you can feel when all of the screw threads are out of the hole. You can then remove the plug quickly with the minimum amount of oil running down your arm. You will also have the plug in your hand and not in the bottom of a pan of hot oil.

Change the oil filter every time you change the oil. The engine should be at operating temperature.

The oil filter is the spin-on type.

To replace the filter, you will need an oil filter wrench. Loosen the filter with the filter wrench. With a rag wrapped around the filter, unscrew the filter from the oil pump housing. Be careful of hot oil that might run down the side of the filter, especially on the sixes and V8s.

On the F4-134 engines, the filter is mounted with the open side facing downward so you won't have to worry about oil running down on your hand.

Make sure that you have a pan under the filter before you start to remove it from the engine so you won't make a mess and, if some of the hot oil does happen to get on you, you will have a place to dump the filter in a hurry. Wipe the base of the mounting plate with a clean, dry cloth. When you install the new filter, smear a small amount of oil on the gasket with your finger, just enough to coat the entire surface where it comes in contact with the mounting plate. When you tighten the filter, turn it only a quarter of a turn after it comes in contact with the mounting plate.