Rear axle wheel bearing

First item to check would b the axle vent, if it is plugged it can cause a pressure build up inside the axle and cause a leak. If the vent is open and you still have a leak you will be replacing the wheel bearing oil seals.

This is not a really hard job but it does require a lot of parts be removed to get to the seals in question. You need to shut off the air suspension if equipped (switch in the trunk left side) then remove the rear axle shafts which means removing the ABS sensors, brake calipers and rotors. Then draining the gear lube and removing the housing cover. Next you remove the pinion shaft bolt and slide the pinion shaft out (Do not turn or move the axles or drive shaft with the pin out!). Now you can push the axles in slightly to remove the axle retaining clips. The axles will now pull out of the housing. I like to reinstall the pinion pin just to hold things together as soon as I remove the clips and slide the axles out just enough to clear the pin. That way if I do bump something the gears stay in place.

Now that you have the axles out you can remove and replace the seals. Check the bearings and axles for wear as well because now is the time to replace them if worn. (For the price I replace them anyway)

This is also the time to replace things like a rusted differential cover or rusted brake backing plates. Rusted or damaged ABS tone wheels or brake parts that need repair/replacement. I like to check over all of those parts before I even start this type of job and make a list of the parts I can see need repair/replacement. I usually order any interior axle parts that may be worn as well. Easier to return them if not needed than have a vehicle torn apart and need to wait a day or two on an axle bearing.