BMW R1200RT/R1250RT Forum

A Guide to the Hexhead/Camhead Final Drive and Shaft Drive

I've recently had to replace my final drive and shaft on my 2007 R1200RT with ~93k miles. I spent several hours (like 20) attempting to find the best course of action. I'll try to share what I've surmised.

My lawyer would like you to know: This post is posted by some guy who is not a trained mechanic and reflects his personal thoughts and experience when it comes to wrenching on his own motorcycle. This may or may not be correct and he takes no responsibility for ensuring accuracy of any of the info listed below. He's not responsible for any damage or injury incurred by following any or all of this information found here. It's your duty to assume all responsibility for your own mechanical work. If in doubt, take it to a qualified mechanic or dealer.

I'd like to take a moment to thank Jim Von Baden and Anton Largiader . Both were very helpful with not only this post, but also getting my BMW back on the road.


The myth and lore:
In the first years (2004-2006) of the R1200's, BMW decided that they had found some magic oil that would never have to be changed in their final drives. That didn't last very long, as some owners were having problems as soon as 10,000 miles. BMW eventually decided to reduce the amount of 75w-90 final drive oil to 180cc's, while calling for replacement every 12,000 miles.

Prior to 2010, the final drive used a large crown bearing that was not bathed in oil, it was just a standard greased bearing. After 2010, BMW “moved” the crown bearing into the gear oil section of the final drive, and added a vent to the top of the final drive to deal with the heat expansion.


Differences in models:
*All info stolen from Max BMW's parts fiche

RT:
Years: 2005 to Aug. 2006
The RT model came with a shaft drive with 20 teeth and BMW part no of: 33 11 7 665 803
The final drive ratio was 34/13 2,62 and a BMW part no of: 33 11 8 530 077 (Gen 1)
The RT-P (Police model) came with a shaft drive with 20 teeth and BMW part no of: 33 11 7 665 803
The final drive ratio was 33/12 2,75 and a BMW part no of: 33 11 8 530 078 (Gen 1)

Years: Aug. 2006 to 2013 (2010 to 2013 vented)
The RT model came with a shaft drive with 22 teeth and BMW part no of: 26 11 7 706 394
The final drive ratio was 34/13 2,62 and a BMW part no of: 33 11 8 726 895 (Gen 2, vented)
The RT-P (Police model) came with a shaft drive with 22 teeth BMW part no of: 26 11 7 706 394
The final drive ratio was 33/12 2,75 and a BMW part no of: 33 11 8 726 891 (Gen 2, vented)


GS:
Years: 05-07 (K25) Produced: 2003 to Sept. 2007
The GS model came with a shaft drive with 20 teeth and BMW part no of: 33 11 7 665 803
The final drive ratio was 31/11 2,82 and a BMW part no of: 33 11 8 530 076 (Gen 1)
The final drive ratio was 31/11 2,82 and a BMW part no of: 33 11 8 521 838 (Gen 2, vented)

Years: 08-09 (K25) Produced: Nov. 2006 to Sept. 2009 USA
The GS model came with a shaft drive with 22 teeth and BMW part no of: 26 11 7 706 394
The final drive ratio was 32/11 2,91 and a BMW part no of: 33 11 7 726 889 (replacement is Gen 2, vented)

Years: 10-13 (K25) Produced: Oct. 2008 to Sept. 2012 USA
The GS model came with a shaft drive with 22 teeth and BMW part no of: 26 11 7 706 394
The final drive ratio was 32/11 2,91 and a BMW part no of: 33 11 8 526 831 or 889* (vented)
*Note that there are two colors of drives depending on your model color

GSA:
Years: 06-07 (K25) Produced: Mar. 2005 to Sept. 2007 USA
The GSA came with a shaft drive with 20 teeth and BMW part no of: 33 11 7 665 803
The final drive ratio was 31/11 2,82 and a BMW part no of: 33 11 8 530 076 (Gen 1)
The final drive ratio was 31/11 2,82 and a BMW part no of: 33 11 8 521 838 (Gen 2, vented)

Years: 08-09 (K25) Produced: Nov. 2006 to Sept. 2009 USA (2010 to 2013 vented)
The GSA model came with a shaft drive with 22 teeth and BMW part no of: 26 11 7 706 394
The final drive ratio was 32/11 2,91 and a BMW part no of: 33 11 7 726 889 (replacement is Gen 2, vented)

Years: 10-13 (K25) Produced: Oct. 2008 to July. 2013 USA
The GSA model came with a shaft drive with 22 teeth and BMW part no of: 26 11 7 706 394
The final drive ratio was 32/11 2,91 and a BMW part no of: 33 11 8 526 831 or 889* (vented)
*Note that there are two colors of drives depending on your model color

R models:
Years: 05-10 (K27) Produced: Nov. 2005 to Sept. 2010 USA
The R model, up to 1/08, came with a shaft drive with 20 teeth and BMW part no of: 33 11 7 665 803
The R model, after 1/2008, came with a shaft drive with 22 teeth and BMW part no of: 26 11 7 706 394
The final drive, from Aug. 06, ratio was 33/11 2,75 and a BMW part no of: 33 11 7 726 891 (vented)

Years: 10-14 (K27) Produced: Dec. 2009 to July. 2014 USA
The R model came with a shaft drive with 22 teeth and BMW part no of: 26 11 7 706 394
The final drive ratio was 33/12 2,75 and a BMW part no of: 33 11 7 726 891 or 164 or 204* (vented)
*Note that there are like 7 colors of drives depending on your model color, so I didn't list them all

S models:
Produced: Nov. 2004 to Sept. 2006 USA
The S model came with a shaft drive with 20 teeth and BMW part no of: 33 11 7 665 803
The final drive ratio was 33/12 2,75 and a BMW part no of: 33 11 8 530 080

ST models:
Produced: June. 2003 to June. 2007 USA
The ST model came with a shaft drive with 20 teeth and BMW part no of: 33 11 7 665 803
The final drive ratio was 34/13 2,62 and a BMW part no of: 33 11 8 530 077 (Gen 1)
The final drive ratio was 34/13 2,62 and a BMW part no of: 33 11 8 521 895 (Gen 2, vented)


ARE YOU CONFUSED YET? ??? ?
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Model and year interchangeability:


Shaft drive:[/size]As long as the number of teeth are the same, any year/model of drive shaft will fit any submodel (RT, GS, ST, etc.)[/size]


Final Drive:It appears that as long as the number of teeth on the drive shaft are the same as the original final drive, you can successfully swap a ST/GS/RT drive for another. Just note that there could be ratio changes.[/size]For example, I have read that some GS owners who don't ride off road, enjoy the higher gear ratio of the RT drives on their GS's.

How they fail:


Shaft drives:One or more of the four u-joints wear out or fail. As far as I know, there isn't a way to change the grease in these bearings. One of the culprits for premature death of these bearings lies in the fact that water can enter into the rubber boot that covers the end of the shaft drive/final drive. Water washes out the grease and contributes to rusting of the shaft drive. GS riders (or adventurous S/ST/RT riders) who ride through water crossings at or above the level of the final drive can see these water intrusion issues. So, it's important to regularly double check to make sure that the rubber boot is secured. Side note: BMW calls for a white lithium grease, Staburags NBU30 PTM (some riders use AGS Sil-Glyde or Bel-Ray, basically anything that is water resistant and okay for rubber) as a lubricant on both ends of this boot to both help keep it affixed, and prevent water intrusion.Shaft drives can also experience failure of the splines that mate the final drive. From what I've read, and unlike previous generations of BMW motorcycles (airheads/older k-bikes),this typically doesn't happen. It seems that BMW has done a much better job of figuring out the proper metal composition and treatment. BMW still recommends that you use a sticky, grease with moly in it every 12,000 miles. The manual calls for Optimoly TA, but many people use Honda Moly 77, Loctite Moly Paste, or TS-5 (sold by Ted Porter).


Final Drives:Final drives fail in a couple different ways. One way to experience a failure is that one of the oil seals holding in the gear oil fails, allowing oil to fling itself all over the back of your bike. These seals are pretty easy for a moderately-experienced mechanic to replace. The next way for the non-vented final drives to fail is that the crown bearing wears out. The vented final drive don't seem to have this problem nearly as often. Finally, the splines of the final drive could fail, but again this seems unlikely.BMW originally called for a refill of 220 ml when you changed out the oil. Some riders have speculated that this could cause extra pressure when the fluid expands, causing seals to leak and final drives to be ruined. Hence why BMW went down to a refill recommendation of 180 ml. If you run the maths, starting with an initial final drive temp. of 75 degrees F, and ending with a warmed final drive temp of 130 F, you'll see an increase of ~3.84 ml for the 180 ml fill, and about a 5 ml increase for the 220 ml fill. Now, I didn't run the maths to see what that approx. 1 ml does on the inside pressure, but I'm doubtful that it's such a drastic difference to cause problems.

How to know if you have problems:


Ideally you want to catch this problem early. I know of one of my riding buddies who found out that his FD had failed him when he noticed his rubber boot was on fire, as he was traveling at 70 mph down the interstate. Not ideal.Shaft drive: Other than a catastrophic failure, the only way to know if you're having an issue is to swing down the final drive and inspect the shaft. It's a fairly simple process that has already been described here on the forums, here's the link http://www.jvbproductions.com/R1200_Final_Drive.html. The shaft knuckle should move up/down and side/side without issue, as any binding or bearing “notchiness” is going to indicate a problem. Some surface rust is probably okay, but that would put up a “yellow light” in my book. Severe rust (for me personally) is a no-go. There have been only a few reports that I've read about the front knuckle failing, but it could happen. Water is less likely to attack this knuckle due to how the swing arm is aligned. For GS/GSA riders, you can extract the shaft drive from the swing arm, S/ST/RT riders you'll have to remove the swing arm for full inspection.


Final drive:One way to inspect the final drive (that isn't covered in oil from an oil leak) is to place the bike into gear, then onto the center stand. Grab the rear wheel at the 12 and 6 O'clock position and attempt to feel if there is any play in the final drive as you rock it toward and away from you. Repeat this procedure at various other positions around the clock. If you discover play, have someone hold the rear brake and test again. If the play goes away, it is the final drive pivot bearings. If play remains, the final drive bearings are loose/toast.Another way to to place the bike in neutral and on the center stand. Slowly and lightly spin the rear wheel with your fingers, both forward and back several rotations, feeling for any resistance or notches in the final drive bearings. I'd recommend taking off the rear brake caliper, as this will further reduce friction/other problems. You can do this with both the rear tire on and off the bike, but it will probably be more pronounced with the tire on. (This is how I discovered that I had a problem)Yet another method is to drop the gear oil and inspect for metal flakes/shavings. The speed sensor is slightly magnetic, so there may be some debris on that. Anton notes that up to a pea-sized lump is not unusual. The gray metal residue should feel like wet chalk, and not gritty, despite what it looks like. If it is gritty, especially with chrome shiny bits, the bearings are failing.Checking the pinion bearing is also ideal when you have the drive swung down. Anton notes there should be no side-to-side movement of the shaft[/size]. He goes into greater detail in the link.*[/size](*Note that I had 85% of this all written up before I found his website... sigh... I'll blame my crappy Google-fu)[/size]Finally, noise is another determinator of final drive problems. I noticed a pronounced, rhythmic grinding sound, especially at low speed when I was turning right.Don't tell my mother, but sometimes I ride without my earplugs in, and on desolate roads, I'll pull in the clutch and shut off the engine, just to hear for any potential problems. YMMV[/size]

So I have a problem, now what - Replacement or rebuild options:
Rebuilding the shaft drive:Gridlock Motors/BeemerUberAllis provides joint replacement services, even if your driveshaft has had catastrophic failure of the joint. They quote $530 to $630 for the rebuild and installation (parts/labor).Machine Services Inc. in Greenbay, WI will replace the worn u-joint, but do not replace worn or broken yokes. One quote I saw on the forums mentioned that the price was $260 for this.[/size]


Replace the drive shaft:Ted Porter's Beemer Shop sells a new rebuildable driveshaft for some models from a company called Ei. They sell for $649 (as of this writing)[/size]You can also source a new shaft drive directly from your favorite dealer. I believe that list price is $1157. Now, that's a lot of clams, but remember that all new BMW parts carry a 24 month, unlimited mileage warranty, so again, YMMV.[/size]


Rebuilding the final drive:(Note that I did not do an exhaustive search on ALL the places that could rebuild your drive)Anton at Virginia Motorrad is equipped to rebuild these drives. His website notes that a typical repair is ~$750-850 (I would assume that you'd get the standard 24 month, unlimited mileage warranty by BMW, but I don't know that for-sure).[/size]Tom Cutter at “Rubber Chicken Racing Garage” is fully-equipped to rebuild these drives.[/size]MaxBMW does “upgrades” from stock ratios to various other gearing ratios, they do list some prices on their website.[/size]Replace the final drive:BMW will gladly sell you a brand new one for $2342. Again you'd get the standard 24 month, unlimited mileage warranty from BMW, so this may be a viable option for some.[/size]Used final drives seem to be available from various parts brokers and eBay. If you're bike is newer than 2006, I'd seriously think about getting a 2010-2013 vintage, as these will have the upgraded bearing/vent. Wherever you buy one from, make sure you can clearly see everything on the final drive, including the splines. I've personally seen many a final drive with splines beyond repair on K75/K100 eBay auctions.[/size]


I'll do my best to update this post with any new information that I receive.Hopefully you never need any of this info! [/size]

Awesome report. Tank you. I have book marked it for possible use in the future.

Much appreciated.&nbsp; Hope I don't have to use it of course, but very handy info to have.

Much appreciate the time you put in to gathering all this information, it is really helping me to source a final drive option for my 06 rt, do you know if different ratio final drives will mess with the abs and speedometer?

Thanks again

Guillem