[Chevyman2]

Just smart to change diff fluid and oil at or within first 1500 miles.

[Cgocifer]

I get that some folks like to change the diff fluid, but that is a personal decision. Nowhere that I've seen indicates a manufacturers recommendation to change the diff fluid at 1500. I may change mine at 3000 or so after the gears have had time to get acquainted. Then again, I dont track the car and pretty much baby it. The 1LE rear end doesn't experience the infamous groan like the standard SS rear.

[MackSteelPrivateEye]

Coming up on 15k miles on mine...never changed the diff fluid. No issues as far as I know.

[JCunningham]

look at diff fluid at 500 miles on anything it is metallic black. Ask a gear shop when to do it. they will tell you 500 miles. follow the performance guide. Change the diff at 500 miles and again at 1000-1500. Its 1.2 qts of fluid and just a drain and fill plug. it will be shit at 500 and the 1000-to 1500 will flush all the crap from breaking it in out. Has nothing to do with the grown problems. all diff gears have a 500 mile break in. https://my.chevrolet.com/content/dam...tion-guide.pdf this manual shows what you should be doing with new vehicles but gm doesnt want to tell you you need to spend money on it that soon.

[Cgocifer]

Originally Posted by JCunningham

look at diff fluid at 500 miles on anything it is metallic black. Ask a gear shop when to do it. they will tell you 500 miles. follow the performance guide. Change the diff at 500 miles and again at 1000-1500. Its 1 qt of fluid and just a drain and fill plug. it will be shit at 500 and the 1000-to 1500 will flush all the crap from breaking it in out. Has nothing to do with the grown problems. all diff gears have a 500 mile break in. https://my.chevrolet.com/content/dam...tion-guide.pdf this manual shows what you should be doing with new vehicles but gm doesnt want to tell you you need to spend money on it that soon.

Pretty much the same as the 2018 manual. Again no reference to the diff fluid.

I've followed new vehicle manufacturer recommendations my entire life and have run cars and trucks to 150k miles with bo issues. My Chevelles new Moser M9 rear end also never had any fluid change recommendations except after 40k miles.

Dont over stress and overdo everything. Just follow the manuals and drive the car. Maybe if I planned to keep the car long enough to hit 100k miles. Lol I drive mine maybe once a week during the good weather months.

[GTSLOW]

Originally Posted by JCunningham

look at diff fluid at 500 miles on anything it is metallic black. Ask a gear shop when to do it. they will tell you 500 miles. follow the performance guide. Change the diff at 500 miles and again at 1000-1500. Its 1 qt of fluid and just a drain and fill plug. it will be shit at 500 and the 1000-to 1500 will flush all the crap from breaking it in out. Has nothing to do with the grown problems. all diff gears have a 500 mile break in. https://my.chevrolet.com/content/dam...tion-guide.pdf this manual shows what you should be doing with new vehicles but gm doesnt want to tell you you need to spend money on it that soon.

Even with the cooler and all it's only 1 quart? That can't be right?

[JCunningham]

the cooler uses tranny fluid that comes from the transmission. ya your right its 1.2qts ill edit my post so you need to buy 3 quarts to do the rear twice

[1CEBITN]

Mustangs in your rear-view...

Just enjoy the car, it has a warranty if anything goes awry...