my '08 M8540 operates flawlessly including the 4wd. recently, disengaging the 4wd is problematic in that the lever seems to hang up 3/4 downward toward the floorboard, and requires some coaxing to fully disengage.were it not for the 4wd dash light, i wouldn't have noticed... previously, it was very fluid to fully disengage. your thoughts on why it hangs up like this suddenly? is there some clutch/linkage adjustment? lube areas? have yet to crawl under. thanks in advance.