what is the max fill quantity? Also in 2WD I assume the case is just a straight throughout connection and little harm until a user selects 4wd. you mentioned you have seen 3 now, are these new units right off of the truck or customers trucks that have had issues? IE why did you check and what harm has been done? I'm going to check but at 30K miles either I'M lucky, its full, or in 2wd it doesn't really matter, and I'm lucky what little 4wd i have done hasn't caused an issue.