well I decided to do a diff fluid change on my 2015 G80 Diff in my silverado. I hand pumped out and filled with almost 3 qts of SYNpower 75W90 gear lube. Wanted to get the break in stuff out. FF was very dark but didnt smell burnt or anything, Fill plug magnet had almos nothing on it. I'll be happy back there till I get to 100K miles.
2015 Silverado Crew cab, 10K miles
2015 Silverado Crew cab, 10K miles