2020 Mazda 3 Rear Diff factory fill 45,325mi

[Rally2045]

Replaced my rear diff fluid due to people having early failures of the diff on this car. Not sure if it was from under filled diffs at the factory or actual mechanical flaws.

Anyways fluid looked fine when I changed it. The factory fill should be Mazda 75W-85 SG1 GL-4

 

[JavierH19]

It'll be fine, that has break in metal and it's not too high. Believe i once saw a uoa of a diff with a thousand ppm so it was pretty much shot. How cold does it get where you live. I'm always biased towards using 110 or 140 for diff life if it doesn't get too cold.

 

[fantastic]

Not much to add from their notes mentioned but it is neat to see what the add pack is on gear oil. Is there any idea around what mileage these differentials are starting to fail..100k?

 

[Rally2045]

Not much to add from their notes mentioned but it is neat to see what the add pack is on gear oil. Is there any idea around what mileage these differentials are starting to fail..100k?

Keeping in mind I have no idea what people are doing to their cars, including mismatched tires or drivetrain abuse in the parking lot, I’ve seen some early failures from like 25,000-45,000mi. Some of them apparently were from factory QA issues, less than .1qt of fluid in there.

Anyways that was part of the motivation for changing it. I had about the correct quantity and as the analysis pointed out everything’s fairly normal.

 

[Rally2045]

It'll be fine, that has break in metal and it's not too high. Believe i once saw a uoa of a diff with a thousand ppm so it was pretty much shot. How cold does it get where you live. I'm always biased towards using 110 or 140 for diff life if it doesn't get too cold.

Gets down to -15F ish here potentially I live in the mountains. I’ll stick with the overpriced Mazda fluid for now, then I’ll look at other options.