My 2001 Durango 4.7 threw a lifter this past summer. Got all the parts finally and put it back together. Had to replace rt. side head because when the lifter exited, so did part of the head.
So I'm filling it with the juices of life (h20), and I hear leakage...but its not coming from the head I replaced. I get under it to see fluid coming out of the bell housing. Million dolla question, are there freeze plugs on the rear of the block? Seems funny that they would go now. Its sat in my garage for 4-5 months. And when the lifter went, it didn't leak any coolant at that time, only oil, lots and lots of oil.
Just dumbfounded as to how it can just go by pouring coolant in.
Others have suggested the opposite got hot and warped, and of course I can't see up there. So I'm kinda left with pulling xfer case and tranny to see where its coming from. Or...if anyone has a better idea, cause im all ears.
btw, my wife is super p....d because of the amount of money in this pos. (I didn't want to buy it)

 

Not sure on the 4.7, but the 5.2 and 5.9 engines do have freeze plugs on the back of the block.