I have a quick question about replacing the rear main seal. I haven't found very much information in other threads. My truck is leaking oil and I think that it is coming out of the rear main seal. How much work is involved in replacing the seal? If I just have to drop the oil pan, I am up for that, but if I have to pull the transmission, it will just have to leak for a while. Also is the oil pan hard to drop with the IFS in the way?

 

In my experience, its best to remove the front diff before trying to remove the oil pan. You can try to jack the engine up, but it won't move enough for you to do very much. The main seal is a typical round rubber seal, and its one-piece. the tranny will have to come out, the flywheel has to come off. Then you can remove the rear seal assembly which is an alloy casting with about 5 bolts holding it on. So an operation like this would be similar to replacing your clutch, which, you might want to do while you have it this far apart... and, while you have your front diff out, do your aussie up front, and go ahead and install new CV axles. Then, put it all back together and you're good for another 1/4 lifetime!
whew....