When Removing Engine and Transmission Together as a Unit...
 

Do I need to drain the Transmission oil first? I am not planning on separating the two this time. Will it be a big mess? Or will it be OK?

I didn't drain mine, no spills.
Just don't turn it upside down!

No you don't but if your plan is to drain it when you drop it, then I would do it before, much easier.

No need to drain the trans. Nothing will leak.

But be aware, even though you will have drained the engine oil, it will still be messy. You may want to have a good selection of plugs to prevent your oil lines from dripping.

Ask me how I know. :)

OK, thanks for the tips!

Even if you separate it the trans won't leak.