I have a '99 TRD V6, Man Trans with just over 60k miles. It has started to throw oil out of the front diff. breather tube. I have had the case serviced and no problem other than a possible blocked breather was found. It still feels like everything is "bound up." And, it doesn't seem to free wheel like it should. Because of the heat her I use 80w-90 gear oil. Any thoughts on what to check next.