Rear freeze plug leaking????

[jeffh355]

I'm going to assume I have a rear freeze plug leaking but it seems to be leaking coolant between the trans (NV3550) and the bell housing adapter which is 3" higher than the engine to bell housing itself. I'm pretty sure water doesn't travel uphill to leak from where its leaking. It's been leaking for a while so when I replaced the heads last month I verified that it's not dripping down from above. No doubt in my mind it's the rear freeze plug just don't understand how it would leak out at the trans instead of the engine to bell housing? Thoughts? Guess I'll find out when I pull the trans out.... eventually, just not high on my list of fun projects.

 

[blubuckaroo]

That IS odd!
Are you sure it's coolant?

 

[jeffh355]

That IS odd!
Are you sure it's coolant?

Yes, 100% it's coolant. Plus I beat the heck out of this Bronco climbing in 4 wheel low and don't seem to have any clutch slippage issues. It leaves about a teaspoon full of coolant on the ground after driving and sitting over night.

 

[blubuckaroo]

I just crawled under mine and I just don't think it would be possible for a rear freeze plug to drip from there. I would pull the clutch boot off and take a look inside the bell housing.
If you look at the top of the bell housing, there is a rib cast into both sides that would channel the coolant from a leaky intake manifold to the top of the adapter. The coolant would go through the adapter bolt and right down the front of the tranny.

 

[DJs74]

Heater hose routing? Any chance the heater hose connected to the heater core has a leak / drip running down onto the top of the bellhousing?
I have a C4 but my hose routes around the cylinder head and down along the valve cover rail. I know my suggestion might seem "out there" but I have to say it might require some unconventional thinking to solve this one?????

DJs74

 

[jeffh355]

I swear I've crawled all over this is make sure it wasn't leaking from somewhere else. Last thing I want to do is pull my trans/transfer case! I will check for the 100th time but the inside of the vehicle (heater core area) is dry as can be and with the body lift I can see all around the transmission so I would be able to see if it was leaking down from above. I'll pull the clutch boot tonight and see if I can peek inside.

 

[DJs74]

The only other possibility I can think of is if there is a plug in the rear with a crack or pin hole and once the coolant system is pressurized (when heat begins to build) it might not be a drip but rather a shooting stream of coolant directly aimed at the bellhousing/ transmission. Kind of like putting your thumb over the end of a garden hose and you get a direct power stream??????? My best guess brother, good luck and keep us posted

DJs74

 

[phldwsnoc1]

Tracer products makes a coolant dye that takes all the sport out of finding leaks. I have used it professionally for years. When in doubt, I use it every time. Good luck!

 

[jeffh355]

Pulled the clutch fork boot and its dry as a bone as far as I can see inside the bell housing. I'll look into the coolant dye tomorrow but it looks like the trans is coming out. I already use a blue coolant so it's pretty easy to see. I did crawl all over the trans and back of the engine again this evening, looks and feels dry as could be! This is so annoying.