Post 4 is from a guy that works in an auto repair garage and sees a decent amount of MB cars. " The diff on those very rarely fails. I'd replace it with a used one before ever thinking about a rebuild. "

Looking on car part, Search Results userSide=&userDate=2000&userDate2=2000&dbModel=49.26.1.1&userModel=Mercedes%20ML%20Series&dbPart=440.1&userPart=Carrier%20%28see%20also%20Differential%29&sessionID=820000000000000000004088503&userPreference=price&userIntSelect=1223935&userUID=0&userBroker=&iKey=&userPage=1

They are showing 1998 to 2004 ML 320 / 430 / 500 to use the same rear diff. They are showing 49 pages of diffs, this is a sure sign that there isn't a market for used diffs. ( RE they rarely go bad. )

A few misguided yards show the used diff for over $ 700 one shows a rebuilt unit for $ 1,300. There are 4 pages of diffs for under $ 100 from reliable sources I've bought from before.

Why would you want to spend more than the car is worth by buying a MB reman at youir estimated $ 3K