BMW R1200RT/R1250RT Forum

Looks like the dominant recommendation is to use two different oils in the cases. BUT, not sure why, if they specify the same weight why not use the same oil? I have a 1L of Castrol Syntrax (with LS modifier) in 80-95 is there ANY issue with using it in both cases? Thanks!

I have 1L of Valvoline Synthetic 75-90w as well, also as LS modifier. Apparently not that easy to find non LS fluids in the states?

Will be going into the 8k miles 09' RTP

IIRC, for my 2007 Hexhead, the original gearbox oil was 80W-90 and the final drive was the fancy 75W-90 Syntrax Longlife. The latter being changed at the running-in check and then in for life.

AFAIK, the spec. now is to use 75W-90 in both gearbox and final drive, 1L should do both.

Not sure whether oil with LS modifier should be used.

SD1 wrote: ↑Wed Feb 08, 2023 12:19 amI have 1L of Valvoline Synthetic 75-90w as well, also as LS modifier. Apparently not that easy to find non LS fluids in the states.

I think this is the BMW OEM stuff, https://www.bobsbmw.com/store/product/b ... -one-quart



"I believe this oil is made by Castrol but I can never find it in local stores.
This is a special lubricant, so why mess around with anything other than OEM."

I use 75-90w in both. 99% of car gearbox oil will do. I use Smith and Allen Fully Synthetic oil.

I found some Bel-Ray synthetic that did not have the limited slip friction modifiers and used that in both holes. I will say the first ride I took on the bike yesterday was about 40 miles and about 3/4 of the way through it, the gearbox decided that Neutral was an optional selection. I was a bit concerned as it was my first outing on the bike, but it was intermittent and when I got back home I could not replicate it.

Today when I swapped out the fluids, the gearbox fluid was IMO significantly polluted and as soon as I saw it thought my no Neutral was going to be a short lived problem and sure enough, the bike is MUCH happier with the fresh gear and final drive juices.

I was also tempted to do the service with the tire on but I did not have a T25 that I could squeeze in to remove the sensor/fill hole. I used 180ml of fluid in the final drive.

Due to the condition of the fluids, I am going to do a second swap at a fairly short interval, maybe in 1k miles +/-