I wrote this up while waiting to do my Civic Duty in Jury Duty, so you get the next installment early!
Probably one of the easiest jobs to do on the R1150RT is to change the final drive oil and/or the tranny oil. I was going to post another step-by-step walk through, when I just remembered Mitch "Joe Frickin' Friday" Patrie has already written and posted an excellent manual that covers almost all of the servicing on the 1100's with many annotations for the differences for the 1150's as well. I'll just post my thoughts and addenda here for the 1150's.
BMW recommends the same heavyweight gear oil for both tranny and final drive, namely SAE 90 API GL 5 hypoid lubricant, but they also recommend Castrol MTX 75W-140 GL 5 for the tranny as an alternative as well. Many have sworn by the Shockproof Heavy racing oils ability to smooth out the box of rocks that is the BMW tranny, but you're on your own about that. I've been using it for the last 32K miles and it still sounds like it did when new--like it was coming apart with every other shift! Either way you'll need just over 1 liter of oil, as the final drive takes 250 ml and the tranny takes 800 ml. I find usually that they both take just a skosh more to get the level up to the bottom of the threads as called for in the manual, so you might as well buy two liters/quarts so you don't come up short.
Change the oils at operating temperature. Especially for the tranny and final drive that means ROAD TEMPERATURE, not sitting and idling which doesn't warm up the tranny or final drive. (duh! Don't laugh--many have done it).
DON'T FORGET NEW CRUSH WASHERS! As Mitch reminds you in his TechDaze manual, the R1150RT uses different size crush washers from the 1100 and if you just waltz into your dealer and ask for a crush washer kit for "an RT", if the parts person is not on their game, you'll likely get one for the 1100. I've seen this happen to at least two different people at TechDazes so far and you'll have one extra small, but short a large. You should not just re-use crush washers once they're crushed. There are three sizes: Small 18mm O.D. used for the final drive drain and fill plugs; Medium 20mm O.D. used for the engine oil drain plug; and Large 22mm O.D. used for the fill and drain plugs on the transmission.
Other specific tools you'll need:
6mm hex wrench/socket for the final drive fill plug
19mm socket for the final drive drain plug
8mm hex wrench/socket for the tranny drain and fill plugs
Torque wrench (make sure 23 and 30 Nm is in the meat of the range)
You may need adapters to convert sizes for wratchets/breaker bars/torque wrenches
A breaker bar is optional, but it does make short work of the drain and fill plugs.
You need some sort of funnel. I've got quite a collection on my shelf as I kept trying to find one THAT WORKED! Even the crooked one the dealer sells does not go in the 1150's small final drive fill hole and can make a real mess. I finally found one at a dirt bike M/C shop (a MeasuFlow, I think) with a liter sized container--with a lid! It also had graduation marks on the side, a long, clear, flexible tube, a nifty twist-to-shut-off valve feature, a small end piece that fits inside the filler hole, and a cap for the end as well. Gear oil is highly viscous and you'll wait all day trying to get all the oil out of the funnel--it usually waits until you put it on your shelf or toolbox to discharge the rest of its contents. Having a lid and cap lets you just put the whole thing back till next time.
You can buy the gold-plated plastic BMW tranny drain device, or make a flume out of a milk or shampoo bottle, or a trick I learned at Sean Daly's Tech Daze: cut a ~10" scrap of 1 1/2" ABS pipe with a notch cut out.
Either way, you still should put some aluminum foil up behind the footpeg plate and over the cat. Roll the back edge over to help keep the oil from dripping off the back edge. That stuff smells bad enough as it is without burning it onto the cat!
It is a good idea to crack/remove the fill plugs first, so--in the worst case scenario--you know you'll be able re-fill it before you drain everything out. This also prevents a vacuum and helps it to drain faster. The torque values for the 1150's final drive bolts are both 23 Nm, the larger tranny bolts are both 30Nm.
The only other coments relate to the engine oil change:
Mitch's TD Manual is spot on--don't forget to warm it up to five bars and then 5-10 minutes on the side stand first to drain the oil cooler and galleries before putting it up on the centerstand. Another trick I learned at Sean Daly's TD was to use a sharp punch or awl to punch a hole in the bottom of the filter. After all the rest of the engine oil drains out, if the filter is empty also, it makes much less of a mess taking the filter out. Also, Fram oil filter wrench Type: "B" fits the BMW filter and cost me USD 3.49 at my local AutoZone.
Here are some more pics illustrating the steps:
Remove tranny fill plug:
Install drain flume and remove drain plug:
After re-installing the drain plug, fill with 800-900ml of gear oil (BTW, this is not the MeasuFlow)
Remove final drive fill plug.
Remove final drive drain plug. Note the proximity of the bucket to catch the oil. You can also use those "Big-Gulp-type" glasses/plastic tumblers. Otherwise, you'll drip oil all over your rear wheel and rim.
After thoroughly cleaning off the magnetic insert (and looking for large pieces) and re-installing the drain plug, fill with 250-300ml of gear oil.
Congratulations! You're done till the next service interval.