I read an interesting chain of comments on the internet that I thought I would share w/ this group. The site: http://www.eng-tips.com/gviewthread....d/89/qid/59275

Of particular interest: When the oil in a transfer case gets really hot, there are two possibilities: too high a viscosity and too high the oil level. Under both conditions excessive churning of the lubricant may lead to a substantial temperature rise that may shorten the lubricant life substantially.