Was doing oil, oil filter, fuel filter, air filter and greasing the 3 fitting on my stock 06. I'd plugged in the block heater in case I needed to move the truck b/4 starting work. Crawled under found reddish liquid in ground, bell housing and farther up on passenger side of engine. Looked it over real good saw a 2 to 3 inch rubber hose connecting two metal pipes. This connection was the problem, so got out an 8mm(5/16") 1/4 inch driver & tightened the worm drive clamps. From what I read on diesel truck resource 06-07 had this problem until the clamps were replaced with constant pressure clamps. Easy fix for a problem that could be bad on the road. You can find this little hose right near the automatic lube dip stick area. Tough reach etc.