The underbelly of my 4runner was starting to get coated with gear oil around where the rear companion flange hooked up to the rear propeller shaft. I decided to go ahead and replace the seal in there. This was my first time replacing the seal and I actually ripped the first one I bought from Toyota of Palo Alto. I ended up having to drive the G35 over to Piercy Toyota in Milpitas to pick up another seal ($5). I didn't have anyone around to help me film, so the video footage is partial, but it's better than nothing and gives a general idea of what's required to get to the companion flange to replace the seal.