So it turns out that Marshmallow (1998 XJ 4x4 4.0 AX15) is leaking from the freeze plug on the back of the cylinder head and I suspect also from the lower one on the back of the block. The coolant pretty much pours out as fast as I pour it into the radiator.

My questions are:
1.) Do I need to pull the engine or transmission (AX-15) or both?
2.) If I have to remove the engine, should I remove the tranny/tc unit first, then remove the engine?

 

Easiest way I've heard about is removing the intake and exhaust manifolds. I've heard some people doing this then tilting the motor. Shouldn't have to touch the tranny. However if you do remove the motor it would 100x easier to get to. But mostly I've heard what I first said.

 

Yeah, I would replace the five on the side of the block as well. But the ones that are leaking, and are the ones causing me to think about pulling the engine itself, are on the back of the cylinder head and on the back of the block.

 

You may have found your source of "brown goop".

 

+1

I was going to say that this is surely related.

 

Brown goop from ignorant previous owners has caused a freeze plug to fail on my jeep. I replaced all of the side plugs with brass. Your best bet is going to be to remove the cylinder head to replace that one and I think you can get away with dropping the transmission some to get to the rear. Fun stuff. Luckily I didn't have to replace those on mine