Front and Rear axle fluid

The rear one is easy:
Get two qts of gear oil 90 weight or 140 if you go up steep hills (refer to owners manual). If (and you most likely do) have a limited slip differential, you also need the limited slip additive ($10 or so).

The dealer recomends using synthetic oil and so do I.

Gasket should be available at any auto parts store for about $7 bucks, and the gear oil is about $11/qt

1. Lift the rear end by the frame, not the axle.
2. Remove the rubber plug on the differential.
3. Loosen all the bolts, and remove all but the one at the top.
4. Pry the cover loose with a large flat screwdriver, but not completely.
5. Let the fluid drain slowly into a container.
6. Remove the top bolt and the cover.

This is the part where you visualy inspect the gears for wear, and clean the gunk with a lint free rag.

7. Clean the old silicone off the differential and cover with a putty knife. Don't scratch it.

8. Place the new seal on the differential cover and put the top bolt through the hole; attach the top bolt. Then the bottom, making sire the seal is in the right place.

9. Replace all of the bolts as you would when replacing a flat. (Alternating side to side and top to bottom)

10. One the cover is back on tight, add the additive first, then the oil through the hole where the rubber plug goes untill it begins to flow out.

11. Replace the rubber plug and clean the oil off the differential.

12. Drive for a couple of miles and check for leaks.

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The front differential is just about the same, but much more of a pain in the @$$.

The plug is actually a bolt, and the front axle has to be dropped if you need to replace the seal. Also, if you have the "sport" model that had the rock sheild, you will have to soak all of the bolts involved with "PB Blaster" or some other serious penetrating lubricant for at least a day before you try to remove it.

If your seal is good (and you dont see any grease at the bottom of your differential) You can get a pump to get the fluid out and put the new one in. But then you dont know how worn your differential is at 100K.

So Here goes:

1. Remove the the rock sheild: 4 bolts. 2 in the front (near the bumper) 2 in the back next to the transmission.
1.A. Loosen the rear bolts first, but dont remove them.
1.B. Remove the two front bolts.
1.C. Drop the front and slide forward.

2. The axle is attached to the frame, and should be supported by the jack when you try to disconnect it from the frame.
2.A. Disconect the axle from the frame and lower the jack. (Make sure you have the axle supported by something like jack stands so that it has enough room for the draining pan, and still enough room to remove the cover and the bracket that ataches it to the frame.)

3. Do the same procedure for the front differential as you did for the rear when draining and replacing the seal and cover.

4. Before you fill the differential with the new fluid, atach the axle to the frame.

5. Use a pump to fill the differential untill the fluid reaches the hole.

6. Replace the plug (in this case the bolt)

7. Drive in 4x4 for bit (like a mile or so) and check for leaks.

You are done.

Instead of paying the dealer $300+ for the service, you spent less than $100 (and if you really love your car you put better quality fluids in it)

in about 30k-60k miles you will do this again for the rear differential and 60k-90k for the front one (depending on how often you drive in the snow or other rough terrain.)

ALWAYS USE THE BEST QUALITY SYNTHETIC LUBRICANT FOR YOUR 4X4. It's cheap insuriance.