Has anyone replaced the cam shaft seal on the rear cyl head?

Mine is pouring oil out.

3.0 lt TF magna

involves removing timing belt, if you belt is near doing, you may as well do it all at the same time

First of all check all of your breathers on both rocker covers are not blocked, if they are the rear bank will pressurise and thus push oil out of the rear cam seal, it will eventually push out in other places too but this will be the first sign

If your timing belt is soaked you will also need to change the timing belt as well

Good point about the breathers, check them first. Put a clean hose on the rear spout on the rocker cover and have a good blow/suck. You will soon find if its clear or not. (engine off of course) To check the belt, remove the front top cover and run your finger over the back of the belt. If your finger ends up dirty with oil you need to replace the belt. Oil weakens the belt. If you need to do so, replace that oil seal and perhaps check the rocker cover gaskets and spark plugs if they are close to needing doing. Bottom crank seal is worth checking too.