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

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    Registered User drneo66's Avatar
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    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 (replacement is 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 (replacement is 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?????


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

    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.

    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. He goes into greater detail in the link.*
    (*Note that I had 85% of this all written up before I found his website... sigh... I'll blame my crappy Google-fu)

    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


    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.

    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)
    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.


    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).
    Tom Cutter at “Rubber Chicken Racing Garage” is fully-equipped to rebuild these drives.
    MaxBMW does “upgrades” from stock ratios to various other gearing ratios, they do list some prices on their website.

    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.
    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.

    I'll do my best to update this post with any new information that I receive.
    Hopefully you never need any of this info!
    Last edited by drneo66; 01-18-2020 at 04:19 PM.
    Current: 2007 BMW R1200RT, 2013 F800GS
    Former: 1995 BMW K75S, 2009 BMW G650GS
    MOA Member #:150400, IBA#: 37558

  2. #2
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    Great post, but one question. How do you tell a non-vented from a vented final drive?
    Karl
    2007 R1200ST

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    Registered User jandhumphreyme's Avatar
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    Great info, thanks for putting this together.
    So often times it happens that we live our lives in chains
    And we never even know we have the key

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    OldBMWMaster JDOCKERY132445's Avatar
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    Don't try wrenching.

    Quote Originally Posted by kthutchinson View Post
    Great post, but one question. How do you tell a non-vented from a vented final drive?
    If this is your question, I would recommend you take your bike to an authorized mechanic.
    Jerry Dockery
    309 N. 3rd. Ave.
    Kure Beach, NC 28449
    2009 R 1200 RT,1996 R1100RT, 1985 K100RS...too fast to believe.

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    Registered User drneo66's Avatar
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    Quote Originally Posted by kthutchinson View Post
    Great post, but one question. How do you tell a non-vented from a vented final drive?
    The vented drive will have a small protrusion at the top that point towards the saddle of the motorcycle. It has black rubber cover.

    I'll shoot some decent photos and then add them into the original post - thanks!
    Current: 2007 BMW R1200RT, 2013 F800GS
    Former: 1995 BMW K75S, 2009 BMW G650GS
    MOA Member #:150400, IBA#: 37558

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    Registered User drneo66's Avatar
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    Quote Originally Posted by JDOCKERY132445 View Post
    If this is your question, I would recommend you take your bike to an authorized mechanic.
    Meh, we all have to learn some time!
    Current: 2007 BMW R1200RT, 2013 F800GS
    Former: 1995 BMW K75S, 2009 BMW G650GS
    MOA Member #:150400, IBA#: 37558

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    Registered User Dann's Avatar
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    Great write up.

    I would just like to point out that my 07 RT (Built date 2007-05-30) doesn't have a vented FD.

    AFAIK they started installing them later in 2007.
    Daniel
    If you can park it, and not turn around to admire it before walking away, you bought the wrong one.
    2007 R1200RT - IBA # 56396

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    Registered User drneo66's Avatar
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    Quote Originally Posted by Dann View Post
    Great write up.

    I would just like to point out that my 07 RT (Built date 2007-05-30) doesn't have a vented FD.

    AFAIK they started installing them later in 2007.
    Sorry - I made that more clear in the original post. Late 2007 received a drain plug on the bottom of the drive. 2010 is when the RT received a vent.
    Current: 2007 BMW R1200RT, 2013 F800GS
    Former: 1995 BMW K75S, 2009 BMW G650GS
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    Quote Originally Posted by JDOCKERY132445 View Post
    If this is your question, I would recommend you take your bike to an authorized mechanic.
    Why? The OP answered my question just fine.
    Karl
    2007 R1200ST

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    Registered User pappy35's Avatar
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    Quote Originally Posted by kthutchinson View Post
    Why? The OP answered my question just fine.
    Why? Because some people think those who don't know everything should keep their mouths shut. Definitely not how most on here would respond to your comment.
    '13 R1200RT 90th Anniversary Edition

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    Registered User lkchris's Avatar
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    The real myth here is that early drive problems were caused by the gear oil. They were in fact caused by improper assembly. The change interval was added solely for “political” reasons, as all BMW riders are geniuses. The same formula oil remains the only approved oil. BMW cars with same formula gear oil have seen no equivalent procedure changes.
    Kent Christensen
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    '12 R1200RT, '02 R1100S, '84 R80G/S

  12. #12
    Quote Originally Posted by lkchris View Post
    The same formula oil remains the only approved oil.
    If that were actually true BMW would be required to provide the oil free of charge. It is true that the oil used should meet the technical specifications.
    Paul Glaves - "Big Bend", Texas U.S.A
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  13. #13
    Rocky Bow BMW Riders #197 bogthebasher's Avatar
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    Thank you for contributing to the knowledge base of our club. I know it takes a lot of work to do a thorough write-up such as this. Great job!
    Ken Dittrick
    2008 R1200RT (Biarritz Blau)


    Excuses are the rocks upon which our dreams are crushed - Tim Fargo

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    Here's some additional detail on the chronology of final drives. It's specific to the R1200ST (my bike), but should apply to other models.

    There have been five versions of the final drive: two for bikes with Gen 1 IABS and three for bikes with Gen 2.

    2005 and 2006 Models, IABS Gen 1:
    The original final drive has been superseded by a version with the drain plug added.

    2007 Models, IABS Gen 2:
    The original final drive was superseded by a version with the drain plug added, which in turn has been superseded by the version with the vent and revised main bearing placement.

    So if you're looking to replace the complete final drive with a new unit, only the final Gen 1 or Gen 2 versions above are currently available. But if you're looking for replacement parts and have Gen 2 brakes, you have two choices depending on whether your final drive is vented or not.
    Karl
    2007 R1200ST

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