I should note up front what is probably a major reason there is not much info out there on the subject. According to BMW/MINI, the manual transmission fluid is a “lifetime” fluid and does not need to be changed. If you have ever been under a MINI, you’ve probably seen the big yellow sticker on the bottom of the transmission indicating this.
I’ll also note that I relied on a couple forum threads on the Internet to help me. The first was at minitorque where another 2nd gen owner was doing his. That included a link to a thread at the Lone Star Mini Club web site describing an R53 fluid change, which is pretty much the same process (as it turns out).
Now, on to the DIY stuff. First up is getting together the tools and some fluid. Since there is not much info out there, I’m not real sure what all the options one may have. I ended getting some Red Line MT-85 75W85 oil based on some reviews I found on-line. I did note that according to the Red Line web site, their “recommended” oil is actually the MTL 70W80 oil. Royal Purple makes some stuff called Synchromax that may be an option (I use RP motor oil, but found too many poor reviews of the MT fluid to feel comfortable with it). Amsoil has some options as well. Of course, I’m sure one could probably order some MINI OEM fluid as well. I gather that one thing you need to be sure of is that whatever you select meets the GL-4 specification. On a side note, instead of ordering direct from Red Line, I got mine through bimmerworld only because the shipping was a tad cheaper (and even though I only paid for regular ground shipping, since it was just coming from Virginia, it arrived next day).
Only a couple specific tools are needed. The first is a 8mm hex head socket to go on your ratchet. These will be used to loosen and tighten the plugs. I couldn’t find these at auto parts stores, but our local Home Depot had a metric set of hex heads. The other item is a funnel with a tube. I ended up making my own out of a funnel I got from Advance Auto and some 3/8 x 1/2 clear vinyl tubing I got from Home Depot. The 1/2 inch tubing ended up fitting in the fill plug perfectly. I would strongly recommend clear vinyl. To really do things properly, you should have a torque wrench. You’ll need a container to catch the old oil that comes out. I’d recommend a good, thick, large piece of cardboard to help catch spills. So our list is:
- 8mm hex head
- Breaker bar/ratchet
- Torque wrench
- Funnel with tube (1/2” diameter)
- Oil catch pan
I never found anything on this, but I think the transmission should at least be warm to help the old fluid flow out. But all of this may work cold as well. First step is to get the MINI up in the air. I would agree with other posters that the higher the better. I used some ramps I have to get the front end up and then use my jack and some jack stands to get the rear end up as well. You’ll want the MINI as level as possible. While I was able to get under the MINI with the ramps, it was pretty tight.
Next step was to locate the plugs. There are two plugs that have to be located – the lower plug (or drain plug) and the upper plug (or fill plug). On your back, slide up under the MINI right in the center. You should have the oil pan to your right as you look up, the exhaust directly above you, and the transmission to your left (look for that big yellow sticker telling you it has lifetime oil in it). The lower plug should be pretty easy to see. It is right at the bottom center in the side of the transmission.
The upper plug is a little more of a challenge to locate. It is on the same side as the lower plug, but about half way up and toward the rear of the vehicle. So if you were looking at the transmission from the side so the lower plug were at the six o’clock position, the upper plug is at the nine o’clock position.
To drain the old fluid, start by loosening the upper plug (don’t take it out yet), then remove the lower plug (use your 8mm hex head with a ratchet or breaker bar). Be ready when you remove the lower plug for the old oil to start coming out quite quickly. Mine probably shot out about 12 inches and then as it drained it slowly got to where it was just dripping straight down. Make sure you are not in the “line of fire” - some protective glasses or goggles would probably be a good idea.
I let the old oil drain for about 15 minutes. Then put the lower plug back in at least hand tight.
Next, take your hose and thread it down from the top side of the motor until you can get it to the fill plug. Just stick the tube itself directly into the plug hole between a half inch to a full inch. After this, you are ready to pout in the new oil. I think at this point, it will work best to have someone helping you. In my case, my son helped me by doing the pouring while I watched things from underneath. Just take your time. This is the point where the clear vinyl comes in handy. There really isn’t any way to see how full the transmission is. You just have to keep pouring until the fluid stops going in. It is on the thick side going down the tube, so be sure to give it some time to completely drain.
Once full, put the upper plug back in. Then tighten down the upper and lower plug. The info I found indicated these should be torqued to 32 ft-lb on an S and 22 ft-lb on a Justa.
On mine, I ended up using just over 2 quarts to refill the transmission.
And that is it. Pretty easy really. Remove plugs. Drain. Install lower plug. Fill. Install upper plug.
Remember to dispose of the old oil properly. Enjoy motoring!
(Note: a pdf version of this DIY is available for download.)