About 6 months ago I noticed I had a leaking front output shaft on my transfer case of my 1996 LX450. I replaced it with an OEM Seal and OEM bearing. The bearing I pulled out looked and felt perfectly good, but I bought a new one anyway. Today I have oil coming out of the same seal again. I do have a whine between 50 and 70 mph under load. Is there anything in the transfer case that could be causing this seal to go bad??.