This is the feedback I received from a very knowledgeable member from this forum and R3Vlimited when I asked a similar question regarding the replacement of the upper pan gasket. In the end I pulled the motor and did everything with the motor out. Good luck OP!
1) No you do not need to unbolt the tranny. There are two bolts holding the upper pan to the block that you access through holes in the front of the bellhousing though. God help you if you somehow drop the bolts in there though.
2) I used a stock gasket with some Permatex non-curing sealant (the red brush-on stuff) on the upper pan gasket, although if I were to do it again I would use Permatex Ultra Grey RTV. To do this without totally messing up the RTV, you really sort of want to raise the engine up as far as you can (at LEAST 4") by unbolting the driver's side mount from the subframe and either using a cherry picker or a 4x4 on a floor jack and pushing under the driver's side motor mount arm. Just make sure that whatever you do to lift it is SAFE because you could get messed up if the engine crunched your arm between it and the subframe or something. You sort of need to do this to get the upper pan out though...trying to slide in an upper pan gasket with RTV with the pan still under there would not work well at all. Honestly, it is a huge pain in the ass.
The other thing is that oil keep running down from the block and onto the gasket surfaces. Let the car sit for at least 24 hours to minimize this, although it'll still happen and make things difficult.
Topic: M42 Upper Oil Pan (Read 3479 times)