[goatjacket]

Purchased my car with 3,400 miles last week and had no verification that Diff was changed out around 1,500 as so many suggest. Figured it was worth the $50 bucks in fluid to check it out. Sure enough, that stuff was nasty. You can see the smear I pulled off sitting to the left of the plug. Am I correct this is probably the initial fluid change? Not sure how quick this stuff turns dark. The gunk on the drain plug was pretty thick sludge. I was also surprised no fluid came out of the fill port, perhaps it wasn't topped off as much as people say. Regardless I used some extra to flush it out and nice fresh fluid in and I feel more confident in my own maintenance history going forward. Thanks to the previous posts on this subject. Really is useful for DIY.

[ZRacerLE]

Great info. Thank you.

[RLNTLSS]

Wat replacement fluid..is it the same for the 2020 ss?

[Warrior102]

https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1

[TWG1]

I just did my second change this afternoon. I had dealer do it at 500 miles, and today was 1500 miles, so only 1000 miles on diff fluid. I did not take photos, but my fluid was dark and both plugs had a healthy smear on them, exactly like yours. I think I’m just going to get in the habit of doing it with my oil changes.

I also looked into the pumpkin as much as I could see through the fill/drain ports. Lots going on in there - this isn’t anything like the old 12-bolt’s of days gone by. Actually looked a lot like some motorcycle wet clutches I’ve worked on. (Read: $$$$ to replace; which is why I’m going to do these services more than called for.)

[bobby35ny]

I did mine at 2k I think, LOL
I do plan on doing it again after the holidays.

[JROC]

I did mine around 2,400 miles and I think my drain/fill plugs looked worse than yours. Do these rearends get to a point where they stop leaving silver gunk all over the magnets every 1,000 miles or so? You would think they'd eventually get broken in good and stop flaking metal off so much into the diff fluid.

[Alain]

I thought there were clutch packs in the e diff. And not metal gears. Not sure where the metal debris would be coming from.

[breakskeet]

Originally Posted by Alain

I thought there were clutch packs in the e diff. And not metal gears. Not sure where the metal debris would be coming from.

There are still gears in the differential. The clutches are part of the limited slip.

[Chris357]

Originally Posted by goatjacket

Purchased my car with 3,400 miles last week and had no verification that Diff was changed out around 1,500 as so many suggest. Figured it was worth the $50 bucks in fluid to check it out. Sure enough, that stuff was nasty. You can see the smear I pulled off sitting to the left of the plug. Am I correct this is probably the initial fluid change? Not sure how quick this stuff turns dark. The gunk on the drain plug was pretty thick sludge. I was also surprised no fluid came out of the fill port, perhaps it wasn't topped off as much as people say. Regardless I used some extra to flush it out and nice fresh fluid in and I feel more confident in my own maintenance history going forward. Thanks to the previous posts on this subject. Really is useful for DIY.

Looks exactly like mine did in almost exact same situation. Purchased with 3400 miles assumed diff had never been changed.

[minn19]

I did mine at 500 and 1900 miles. I was kind of poo pooing the need for the second change, but it is cheap and easy to do. Glad I listened to people here and did it. It wasn’t as bad as the first one, but definitely didn’t look great. Agreed with others here that I’ll add it to a semi regular service. Maybe not every oil change, but every other.

[ProjectZL1]

EXACTLY HOW I DO IT, WE EVEN USING THE SAME DRAIN PAN!

Originally Posted by goatjacket

Purchased my car with 3,400 miles last week and had no verification that Diff was changed out around 1,500 as so many suggest. Figured it was worth the $50 bucks in fluid to check it out. Sure enough, that stuff was nasty. You can see the smear I pulled off sitting to the left of the plug. Am I correct this is probably the initial fluid change? Not sure how quick this stuff turns dark. The gunk on the drain plug was pretty thick sludge. I was also surprised no fluid came out of the fill port, perhaps it wasn't topped off as much as people say. Regardless I used some extra to flush it out and nice fresh fluid in and I feel more confident in my own maintenance history going forward. Thanks to the previous posts on this subject. Really is useful for DIY.

[goatjacket]

Originally Posted by ProjectZL1

EXACTLY HOW I DO IT, WE EVEN USING THE SAME DRAIN PAN!

I certainly appreciated your video. And you're right, GM is proud of the product. I got off fairly easy as I had some GM rewards to use, which paid for one of the quarts. Next time I'll go through Amazon as others have suggested. I typically am for trying alternatives to fluids, but agree whole heartily with the consensus that a 70K car shouldn't be 'nickel and dimed' with cheaper fluids.

I may schedule myself to change it out again in 1,500 miles (which for me will probably be summer), just to see how quickly this stuff goes bad.

[puppykat33]

https://www.gmpartsnow.com/oem-parts/gm-oil-88862624


17 bucks per quart and cheap shipping. its 25/q on amazon..