F15 Driveline fluids

[kyriian]

Good afternoon
With my F15 getting older, been looking to service my transfer box, and diffs. I will be doing my Transmission in the spring
Vehicle is a 14 X5 35i xdrive

I want to ask if anyone has had issues running the GL-5 Redline fluid in the diffs instead of the very pricey stuff that BMW uses

For references:
Rear differential OEM uses this one according to realOEM: https://www.bimmerworld.com/BMW-70W8...222413512.html

Front differential OEM calls for this one:
https://www.bimmerworld.com/Genuine-...222413511.html

Redline/Bimmerworld claims this is usable as an alternative both front and rear, note the rear weight is different than OEM
https://www.bimmerworld.com/Red-Line...Oil-Quart.html
I also noted Redline sells an equivalent 70w80 as well.

My big question is, what makes the BMW stuff so special to be priced that high (I do know partly because of the logo on the bottle) and whether anyone actually have had issues with the Redline fluids, least personally I have loved Redline fluids every single time I have used it across multiple cars.

I do not intend to run the car till its dead, but I do want to make sure I won't be seeing a damaged diff until the car's replaced.

[markslc1]

I have redline in my diff for 50k now. Great stuff!

[tlow98]

I used the redline in my front and rear diffs for 40k miles. No issues as of yet.

[srybicki]

Same here redline for last 45k

[Warnd4]

2014 X5 35d
I changed both my front and rear differential fluids using Valvoline 75W-90 full synthetic gear oil at 75,000 miles. I’m now at 95,000 miles and car is running smoothe as silk. I will use identical fluid for change out again at 125,000 and every 50,000 miles after

[srybicki]

If you do the transfer case make sure you recalibrate it.

[cfm56d7b]

Originally Posted by kyriian

Good afternoon
With my F15 getting older, been looking to service my transfer box, and diffs. I will be doing my Transmission in the spring
Vehicle is a 14 X5 35i xdrive

I want to ask if anyone has had issues running the GL-5 Redline fluid in the diffs instead of the very pricey stuff that BMW uses

For references:
Rear differential OEM uses this one according to realOEM: https://www.bimmerworld.com/BMW-70W8...222413512.html

Front differential OEM calls for this one:
https://www.bimmerworld.com/Genuine-...222413511.html

Redline/Bimmerworld claims this is usable as an alternative both front and rear, note the rear weight is different than OEM
https://www.bimmerworld.com/Red-Line...Oil-Quart.html
I also noted Redline sells an equivalent 70w80 as well.

My big question is, what makes the BMW stuff so special to be priced that high (I do know partly because of the logo on the bottle) and whether anyone actually have had issues with the Redline fluids, least personally I have loved Redline fluids every single time I have used it across multiple cars.

I do not intend to run the car till its dead, but I do want to make sure I won't be seeing a damaged diff until the car's replaced.

How many miles does your car have?

Our 2015 BMW X5 has 38K miles but it will be 8 years in January 2024. I plan to replace differential and transmission fluids in the Summer 2024.

[tlow98]

The front diff and transfer cases are the most important ones to change due to the volume they hold. Very little!

When I pulled the fluid from the rear I wouldn’t be surprised if it would have never needed to be changed. Looked as new.

[kdad]

I changed the front and rear diffs with 75W90 Liqui Moly. They work great.

Used the OE DTF1 stuff from FCPeueo for transfer case. Works good so far too.

Bmw branded fluids ==> rip offs

[Maverik259]

I used liquid moly for mine but redline would be fine too. All that really matters is the weights. Brand not so much as long as it’s a reputable brand. It also gets tricky if you have the limited slip diff in the back. Then you need friction modifier. But if you have 35i I doubt it.