I found this off of the ExplorerFourm. I wonder if it applies here? I think it would. Especially since it does appear that my rear main seal is leaking.
I think I found the link to that tsb somewhere on this forum. It's tsb 04-19-10 OIL LEAK FROM OIL FILTER ADAPTER - 4.0L SOHC ENGINE BUILT BEFORE 4/1/04. Here, I'll type the bulk of it for you...
Issue: some vehicles equipped with a 4.0 sohc engine, with an engine build date of 4/1/04 or earlier, may exhibit an oil leak from the rear of the engine. The leak may be coming from the oil filter adapter, due to porosity. When the oil filter adapter leaks, the oil may wick around or follow the ladder frame gasket channel to the rear of the engine. The oil leak may appear to be coming from the rear main oil seal and/or the ladder frame gasket area.
Action:
Inspect the oil filter adapter and determine the oil leak source, per workshop manual section 303-00, prior to any repair attempts. If the oil filter adapter is the source, replace the adapter. Refer to the following procedure.
Remove RH exhaust manifold. Remove oil filter. Remove oil filter adapter mounting bolt and the adapter from the engine. Position the new oil filter adapter and gasket to the cylinder block. Install new oil filter mounting bolt seal onto the mounting bolt and install the bolt into the engine block (hand-tighten). Torque the adapter mounting bolt to 42 ft lbs. Install new oil filter. Refill oil to proper level. Reinstall exhaust manifold.
3L2Z-6881-BA oil filter adaptor
3L2Z-6L621-AA Gasket (filter adaptor)
E3TZ-6749-A Seal (bolt)
This seemed to apply to 03/04 Explorer sport tra, explorer, ranger, mountaineer. One poster says you can remove the Y pipe instead of the exhaust manifold. He listed a procedure that I'm sure you can search for on here somewhere.
