Replacing Your 3.9L Oil Pan
TOOLS NEEDED AND SUPPLIES
Gasket scraper (I used a straight razor type)
17mm box end (12pt) wrench
17mm deep socket w/driver (a second 17mm wrench may be subbed)
24mm box end (12pt) wrench
24mm socket (a second 24mm wrench may be used)
½ inch socket
extensions for socket driver (or nut driver with extensions)
1 1/8 inch wrench (for oil pan drain plug
10mm socket
10mm wrench
12mm wrench
Permatex’s Ultra Grey gasket maker (1 tube will be enough)
7 quarts oil (your choice of brands)
oil filter (your choice of brands)
various rags for cleaning
cleaner/degreaser
REMOVAL STEPS
Before you get started you have decision to make. You may want to replace the self locking nuts used in mounting the sway bar (two 24mm and four 17mm).
They are supposed to be only good for one use, your choice, I make no recommendations.
1. Drain oil. You’ll be dropping the pan so you don’t need to drain it completely.
2. Remove the front sway bar. You need to do this so you can have an easy path for putting the pan back on. I did this to avoid disturbing the gasket sealer
while installing the pan. With the sway bar out of the way it almost a straight lift. Use the 17mm box end wrench and deep socket to remove the two bolts
(per side) that hold the bar bushing and mounting clamp to the frame bracket. Use the box end to fit on the head of the bolt. I found that threading the
wrench from the front of the vehicle for the rear most bolt and coming from the back of the vehicle for the front bolt works well. You won’t be able to see
the head of the bolt so you will have to feel around for it. Hold the wrench in place and use the 17mm socket to remove the nut completely off the bolt.
There is a large flat washer on each side of this assembly make sure you don’t leave the head side washer in the bracket. Repeat for the other side.
Once both side clamps are off pull the sway bar to the rear to open up the access to the 24mm bushing bolts. You only need to back the bolt off enough to
remove the nut and to free the bar. There is no need to remove the bolt completely from the bushing. Make sure the bar doesn’t smack you on the head and
remove from underneath the Landy.
Hint: Put the two washers and nut back on the 17mm mounting bolt keeping them together and lessening the chance of losing them.
3. Remove the cast aluminum flywheel cover that is between the rear of the engine and the front of the transmission. I did this step to get uncluttered
access to the back of the engine block where the oil pan mounts. These two parts are close together and I felt it was necessary to make sure the pan
mounting surface was totally clean and free of old gasket material. There are seven bolts holding the cover on. You will need the 10mm wrench, 10mm socket
and 12mm wrench for this. The bottom three bolts will need a 10mm on each side. Next higher up are the two 12mm bolts (one each side) Remove them.
Don’t lose these as they are unusual bolts and would be hard to replace! Next up (the highest bolts) are two (one per side) long 10mm bolts.
Remove the cover and set aside.
4. Install the oil drain plug now, to keep oil from dripping on your forehead.
5. Remove the oil pan. Use the ½ inch socket and extensions (socket wrench, you can use the nut driver for reinstalling) and undo all but two bolts.
These should be from diagonal sides of the oil pan. This should avoid any undue force on either the pan or engine block. Supporting the pan with your hand
or your assistant’s head, remove the last two bolts and lower the pan.
WARNING!
BE VARY CAREFULL LOWERING THE PAN! THE DIPSTICK AND OIL PUMP PICKUP ARE BOTH LOCATED IN THE MIDDLE OF THE OIL PAN, BE CAREFULL NOT TO BEND THESE TWO ITEMS!
6. Carefully use the gasket scraper to remove any gasket material on the engine block. DO NOT USE A WIRE BRUSH OR POWERED WHEEL FOR THIS! YOU DO NOT WANT
ANY BITS OF METAL TO FIND THEIR WAY INTO THE BIG END OR ROD END BEARINGS! Use a cleaner/degreaser to prepare the surface for the gasket material.
7. Thoroughly clean the oil pan mating surface; don’t forget the bolt holes and the underside of the mounting flange. If you are like me, eventually some
debris will make its way into the bottom of the pan. After cleaning the pan mounting surface, I drained the rest of oil and wiped the inside of the pan clean
to remove any leftover debris. If you have a significant amount of sludge in the bottom of the pan you might consider taking it to a machine shop or speed
shop and have it cleaned.
8. Clean all of the oil pan mounting bolts. Mine had a bunch of old gasket material and oil/dirt in the threads. I chased the threads with a 5/16th 18-pitch
die to clean them up.
9. Using the Ultra Grey gasket maker lay a bead of material (about 1/8th of an inch) all around the surface of the mounting flange. Don’t forget to surround
the bolt holes with material. Don’t use too much material as you don’t want it oozing out the sides where it may fall off into your pan which could block you
oil pickup screen!
10. Grab two of the pan bolts and the nut driver with the ½ inch socket. You will use these two bolts to hold and locate the pan on the block while you install
the rest of the bolts. Again your assistants head works well in this step.
11. Carefully, CAREFULLY! Raise the pan up to the block and install the two bolts on opposite sides and ends of the block. Do not tighten all the way, just thread
them enough to make sure the pan stays in place but can still move a bit to install the remaining bolts. To ensure making a good seal do not allow the pan to move
around a lot on the surface of the block. If any gasket material oozes out of the bolt holes use a small screwdriver to remove enough to get the bolt through
without getting a bunch of the gasket material on the threads.
12. Install the rest of the bolts. All of the bolts except the four at the rear of the block are tightened to 10Nm or 90 inch/lbs. of torque.
The four at the rear get 18Nm or 160inch/lbs or torque. I highly recommend tightening the bolts in a crosshatch pattern. Start at diagonal corners
and work your way to the middle alternating sides as you go.
13. Drink a Guinness. Have your assistant get you another one.
14. Reinstall the aluminum cover over the flywheel.
15. Reinstall the sway bar. Attach the sway bar ends to the bushing (24mm nuts) mounts first. Snug them up good; there is no torque setting for these as
they are self-locking nuts. Do both sides. Now thread the 17mm bolts through the frame bracket holes and slip the sway bar clamp holes over them and loosely
attach the bottom washer and nut. Do both sides this way before tightening them down. Now tighten the four bolts side to side and front to rear. Again no
torque values (self locking nuts).
16. Refill engine sump with oil. I found it took almost seven quarts of oil to fill it up. This broke down like this. 5 ½ quarts to initially fill the sump,
½ quart to pre-fill the new filter prior to mounting, ½ quart to top off the sump after a brief running of the motor.
17. Change your filter. I can usually fit almost ¾ a quart into the filter prior to fitting to the engine.
18. Start the engine and look for leaks. I let the engine warm up and then ran it at 2,000 rpms for about two minutes to get the pressure up and check
for leaks again.
19. Drink the rest of your Guinness while watching your assistant clean up the mess!