Hello,
My 1999 Durango 5.2l is dropping a quarter sized drop of antifreeze off the back right corner of the trans pan. I can't trace the leak anywhere, and if I didn't know better I'd say it was leaking straight out of the trans pan. I even pulled half a quart of ATF just to make sure the transmission cooler core hadn't cracked and ATF was mixing with antifreeze, but everything's fine there. I checked the heater hoses, and on the back of the engine I looked for traces of antifreeze possibly leaking on the bell housing and didn't see a trace. The freeze plugs are clean, intake manifold clean, heads clean all around, bell housing clean. Out of obvious options I bypassed the heater core with the heater hoses and still the leak is there. It won't leak if I put a pressure gauge on the radiator and pressure the system, and it won't leak unless the Durango is completely warmed up and driven ten miles or more. I am really baffled on this one. What else is there? I can't, obviously, see on top of the transmission to see where it might be running down the tunnel, but am I correct in still assuming it's the heater core? Even after I bypassed it?

 

freeze plugs maybe

 

my bet, is a head freeze plug, dripping on to the trans case. replace with a brass plug

 

I checked the freeze plugs, there's not even a white trace line from evaporated antifreeze. Also, I did all the freeze plugs 20,000 miles ago. Thanks though, I appreciate the thoughts. Any ideas? I mean antifreeze is still in the heater core, so it could still be leaking. I'm thinking of flushing it with water and seeing if I still get antifreeze, which will eliminate one big fat source right there.

 

did you check the one that's on the back of the block? (You'd have to have the transmission off to check it)

 

Unfortunately yes, well about a thousand miles ago, because I had to have the transmission rebuilt. Poor girl's not having a good year.
Edit, actually I had thought that maybe I damaged a fitting or nipple on the heater hoses, stuffing the transmission back up there or just general moving things around. Which, was somewhat true as the tube into the water pump did start leaking, but I slipped a new o-ring on it and it's at the front of the engine and the current leak is all the way behind the bell housing, so unrelated.