So having just changed all the plugs and filters I wanted to give the gearbox fluid a change too as it's probably never been done before. Having had good experiences with redline MTL in my previous m3's I decided to try it in the m5.
Initial thoughts after the change were that it felt ok, about the same as before I had changed the fluid. However after a few cold mornings it became apparent that my gearbox felt considerably more notchy especially going to 2nd gear when cold. It was a bit notchy when cold before but not this bad. So I decided to try some Motul 300, an oil i have heard good things about.
After the change and after trying it cold for a few days I can say that it was better but still not as smooth as when the original fluid was in there - or had I forgotten how good/bad it was? I now was beginning to doubt myself too.
Anyway there was only one thing left to do. Buy some LT2 from BMW (all 5 litres, ouch!).
So after changing the fluid for the third time and having driven the car for a few days now I can conclude by saying that the BMW LT2 fluid has made my gearchanges feel significantly better than the previous 2 attempts. It's even good when cold and my 2nd gear is also sweet.
I know other members will have different experiences with the fluids I've tried but this is just my 2 pence worth!
You likely have the original fluid. I changed mine for the BMW fluid and shifting was much, much better everywhere. This will happen with nearly any fluid though.Interesting thread. I have had my 2001 with 100k miles for 3 Canadian winter months now and I am not enjoying the notchy 1-2, 2-3, 3-2 shifts when cold. Tomorrow morning will be -10 deg C so I know the 3-2 shift will be damn near impossible for a mile or two. Don't know what oil is in the tranny now, but I have the RP Synchromax ready to go in - fingers crossed.
Anyway, my question is to those who have had new/low mileage M5's: was the shift buttery smooth when new? Is the notchiness just the effect of 100k on the synchro rings? Or was it always notchy 'cos its a heavy duty tranny?
This is good to hear. I will be swapping most of my fluid on my M5 this summer & it's great to know what works best & what does not...You likely have the original fluid. I changed mine for the BMW fluid and shifting was much, much better everywhere. This will happen with nearly any fluid though.
Lol, some folks are never happyOn the M5 I did a change to RP last weekend. I can confirm the experiences of others that it indeed makes the shift smoother and lighter. Almost too light, in fact - I actually prefer a meaty, weighty action, not a car that I can shift gears with just the tips of my fingers.