Re: Leaking Rear Differential Seal?
If I were you, I wouldn't do this job myself because although it is pretty simple, if you use an impact wrench on the pinon nut, you risk destroying the pinon bearing. I did this job on my mom's '04 Explorer last summer and I couldn't get enough torque on the nut by hand (when you're under the car, even with a 2 foot long breaker bar, you're not going to have enough leverage to budge the pinon nut), so I used my impact wrench. I made sure that I recorded the number of turns and everything so that the preload wouldn't change when I reassembled, but I ended up replacing the whole front diff with a used one because the pinion bearing ground itself into bits. If you had a lift where you could use your whole body weight to loosen/tighten the pinion nut by hand, I would say go for it, but if not then I highly recommend that you have a competent shop do it.