XSeries-forum

I would like to change the diff and gearbox fluids on my ancient X3 with 166,000 miles and was wondering if there are any brands used by forum members?

I recall someone on here recommending Red Line gearbox oil as being superior to most of the other brands. Is there any particular differential oil I should use?

I had a transfer case rebuild in 2019 so assume the BMW fluid was changed then.

If you put the last 7 characters of your VIN into Realoem (BMW Parts database copy) it will give you the BMW fluid types under the relevant sections that you can then search for an equivalent type.

X5Sport wrote: Wed Jul 15, 2026 3:46 pm If you put the last 7 characters of your VIN into Realoem (BMW Parts database copy) it will give you the BMW fluid types under the relevant sections that you can then search for an equivalent type.

Thank you, rather an inane question but I'm anxious to keep my antique in good condition. Earlier this year I almost made Calais to the Italian border on one tank of diesel!

It’s the right call. I changed all my auto box & diff fluids at 8 years so for the X6 it will be due again in the next 12 months (assuming I’m keeping it once the iX3 arrives).