l was told it has to be replaced? ls this true?
Found grindings in the differential oil? on 2007 Chevrolet Avalanche
yes the metal will destroy the bearings and seals. you must have it rebuilt or poss bearing replacement
How often do you deal with this shop? what problem/symptom were you experiencing that led to having the diff. oil changed or was it being serviced as part of normal maint.? Or ...never mind.......
what replaced? the differential? if it is making noise and those grindings are shiny metal, YES you have to change the differential...if it is not making noise and those grindings are just black dirt, YES you have to change your differential oil.