I am seeking differential fluid recommendations for my 840. It's time to change the fluid. I am not sure what brand/weight to use.

Cheers

Interested in this, too. Another task in my maintenance weekend.

David, I would go with redline or royal purple in the weight recomended in your owner manual. Your owners manual is your friend. Hope this helps. Take care.

Regards,

Carter

+1

I use REDLINE synthetic. 1x/year

Hello

I will be looking into this and call some BMW dealers.

Hey Prit, let us know. My rear end is itchin' :lol3 Hopefully it's not like the transmission fluid and can be bought in small quantities.

I'm doing the diff as soon as it warms up a little. I completely flushed the trans and torque converter along with replacing the trans filter last summer... what a difference!

Trans was acting up prior to the fluid flush... BMW Stealer said that I would only do more harm to the trans... F THEM!

-JRW

I too am considering a diff fluid change. Taking the Red Line brand as a suggested option, is there any difference in fluid choices if you have the optioned limited slip differential as opposed to the standard issue diff? I seem to recall that the clutches in an LSD are sensitive to a particular viscosity/formula.

Ive used both royal purple and redline, in trannies, engines and diffs.. and I keep going back to redline. There isn't logical reason as to why, they are all type V synthetic oils, but its what I've been running. You WILL notice a slight increase in mpg/hp if you swap all the fluids with either of these brands.

I too am considering a diff fluid change. Taking the Red Line brand as a suggested option, is there any difference in fluid choices if you have the optioned limited slip differential as opposed to the standard issue diff? I seem to recall that the clutches in an LSD are sensitive to a particular viscosity/formula.
In my previous car days, we used 75W90NS. For my E31, I use Redline Shockproof Lightweight per Jim's recommendation (I have a very different differential then the usual...:shifty)

Limited slip diff- I use Royal Purple's Max Gear, No additive needed, Just put and go, It runs the rearend 50 degrees cooler than most others.