Differential & Tranny Fluid Change

I am preparing to change the differential and tranny oil in my 2000 M Roadster. I was reading on the Red Line website that they recommend D4 ATF for the tranny in 1993 - up manuals. Does anyone have any comments on this? Also, they recommend 75w140 gear oil for this model differential. Any feedback is appreciated.

I think you would want to use MTL in the trans, I am assuming this is a manual. Did they even make auto M Roadsters?

Thanks for the info. I'll go with the ATF in the grearbox.

The following is directly from the Red Line website; "The differentials equipped with multi-disk LSDs (1992-up) take our 75W140 (which also comes with the friction modifier already included)."

I'm an old school Harley and Hot Rod guy raised on 90 weight. I'm curious as if you or anyone knows about the Red Line recommendation.

Syn Fluids for M Roadster

I also have a 2000 M Roadster. When I first acquired the car about 3 years ago, it was hard to shift on cold mornings. I finally got time to change the fluid in the trans, and a previous owner had put gear oil in it. I know it sounds strange, but the manuals in these BMW's take a type of fluid that is like auto trans fluid. I used Royal Purples recommended Syn Fluid for mine, and the shifter went back to working perfectly. I also changed the rear differential with Royal Purples recommended synthetic, but could not tell a difference. Since then, I had some work done on the engine, head gasket had blown on track, and the Euro Performance shop that worked on mine also fixed a leaking rear main, and a small shifter seal leak on the transmission. They went back with the RedLine Trans flluid. It works great.

that's the same stuff I have in my ti, it's a standard transmission and LSD too, no complaints here

I emailed Red Line on Sunday afternoon and received this reply on Monday. I appreciate the quick response. Here is the reply;

Thank you for contacting Red Line Oil, in your M Roadster I would recommend the D4ATF as it closely matches the original viscosity and type fluid used in the late model BMW manual transmissions. In your rear differential I would recommend the 75W90, suitable for open or limited slip differentials. The 75W140 is a higher viscosity fluid BMW switched to in limited slip applications starting in MY 2002, I wouldn't expect any advantage or benefit to it's use in your differential.


Regards, Dave
Red Line Oil

Follow up-
I changed out the transmission fluid with the D4ATF and can tell a pleasant difference with shifting. Good choice.

I also used Red Line in the differential. I believe it is a bit quieter now.

Now that you've changed the tranny fluid, make sure you flush and bleed the clutch fluid slave cylinder. I've found that fresh brake/clutch fluid makes a big difference in shifting with my Roadster.

Thanks for the tip. I'll give it a shot.