BMW X challenge transmission rebuild

Discussion in 'Thumpers' started by tele-steve, Sep 2, 2013.

  1. tele-steve

    tele-steve ya' mon

    Joined:
    Sep 28, 2006
    Oddometer:
    267
    Location:
    The Peoples Republic- Rocky Mountain Edition
    So I was 1500 miles into a trip this summer and the mechanical gods thought I was having too much fun. About 60 miles due east of Park City Utah, my counter sprocket sheared on the countershaft. I only had about 7k miles on the sprocket and while the bike as about 15k.

    <img src="https://lh4.googleusercontent.com/-NW7yjRTkI2g/UiPUmE7AGPI/AAAAAAAACkw/TTfKYUMXMtQ/s640/BMW%2520motor%2520rebuild%2520-%252009.jpg" height="640" width="480" /></a>

    Getting home is a story in itself. This thread is about the rebuilding of the transmission to replace the output shaft. It doesn't take long realize that most BMW owners don't work on their bikes themselves. I've only found one or two older videos on Youtube of people rebuilding 650gs. So, I've got a copy of the X challenge shop manual on DVD, a copy of the Haynes manual for f650 singles, and all of you to steer me in the right direction.

    Tools will be purchased, things will be broken, knuckles will be bloodied.

    Stay tuned...
    #1
  2. tele-steve

    tele-steve ya' mon

    Joined:
    Sep 28, 2006
    Oddometer:
    267
    Location:
    The Peoples Republic- Rocky Mountain Edition
    The rebuild is going to take some time, so don't expect for this to happen in a weekend. So far I'm in the dismantling stage. The manual says to use all sorts of special lifts, tools, etc. which I'm hoping to avoid, find work-arounds, make homemade versions, etc.

    Here is what the output shaft splines look like and why I'm undertaking this whole thing...

    <img src="https://lh4.googleusercontent.com/-OiKOTOAenIw/UiPUoATgHfI/AAAAAAAAClE/K6bhyjs9LsY/s640/BMW%2520motor%2520rebuild%2520-%252011.jpg" height="480" width="640" /></a>

    Currently, the bike has had the following removed:
    Rear subframe
    Rear swingarm
    Air box
    Throttle body,
    Oil Tank
    Alternator Cover
    Clutch Cover
    Starter

    <img src="https://lh3.googleusercontent.com/-iwbZ38-6Ukk/UiPUvrDJE2I/AAAAAAAACls/lZtiISvqz1Q/s640/BMW%2520motor%2520rebuild%2520-%25206.jpg" height="640" width="480" /></a>

    <img src="https://lh4.googleusercontent.com/-qlU9bynBPaw/UiPUwUKfmgI/AAAAAAAAClw/bRBdDVUxNLg/s640/BMW%2520motor%2520rebuild%2520-%25207.jpg" height="640" width="480" /></a>

    <img src="https://lh5.googleusercontent.com/-kT5ThR1AHgg/UiPUwUbY0oI/AAAAAAAACl0/7q8RXmu-L9M/s640/BMW%2520motor%2520rebuild%2520-%25205.jpg" height="640" width="480" /></a>

    <img src="https://lh4.googleusercontent.com/-nLlk7VZjVMM/UiPUsBvwA5I/AAAAAAAAClc/RRe6ReqfejU/s640/BMW%2520motor%2520rebuild%2520-%25204.jpg" height="640" width="480" /></a>

    Now, I can appreciate a well engineered machine as much as the next guy, but I swear, some the things on this bike that the folks at BMW cooked up boggle the mind.
    The first was the license plate holder. To remove this one needs to remove 2 bolts with allen key heads, 2 bolts with an 8mm socket, 2 torx head screws, and finally, pull the cable release mechanism from under the seat. Needless to say, by the time I found all of the bolts and screws to be removed, I overlooked the cable release and broke the plastic. There goes $50.
    I know this won't be the last time something like this happens.
    #2
  3. swamp

    swamp U lie&yo'breff stank

    Joined:
    Feb 14, 2007
    Oddometer:
    2,403
    Location:
    lower appalachia, Alabama
    Dont feel bad about breaking things during a fit of frustration . We are men. Killing things makes us feel good. No need for a tag bracket anyways . Zip ties baby zip ties . Good luck on this one .
    #3
  4. imeny

    imeny Been here awhile

    Joined:
    Aug 15, 2010
    Oddometer:
    132
    Location:
    Israel
    :cry

    GOOD LUCK MATE !


    +1

    I am In
    #4
  5. wa_medic

    wa_medic Adventurer

    Joined:
    Jun 9, 2013
    Oddometer:
    43
    Location:
    WA
    Looking forward to this one!

    wa_medic
    #5
  6. mbrick

    mbrick Been here awhile

    Joined:
    Feb 22, 2012
    Oddometer:
    176
    Location:
    West coast red sticker territory
    Leave it to BMW to only use a 1/4" wide spline on an off-road machine.

    Subscribed :D
    #6
  7. an13

    an13 Adventurer

    Joined:
    May 29, 2010
    Oddometer:
    62
    Location:
    Finland
    Watch F650 rebuild videos from http://faq.f650.com/dvd/index.htm#F650 Maintenance DVDs and make note that piston can be disconnected from connecting rod without removing cylinder head from cylinder pipe. There is enough room to just slide cylinder upwards (tilting the engine forward helps) and remove piston pin and leave piston inside cylinder. Thus no need to replace head gasket and press piston rings and piston back to cylinder.
    #7
  8. tele-steve

    tele-steve ya' mon

    Joined:
    Sep 28, 2006
    Oddometer:
    267
    Location:
    The Peoples Republic- Rocky Mountain Edition
    An13, thanks for the reference. I saw that trick and plan on using it.


    #8
  9. KustomizingKid

    KustomizingKid Been here awhile

    Joined:
    Nov 21, 2012
    Oddometer:
    739
    Location:
    Minneapolis
    I woulda just giving it a little weld action and road on hahaha... Best of luck with the rebuild!
    #9
  10. tele-steve

    tele-steve ya' mon

    Joined:
    Sep 28, 2006
    Oddometer:
    267
    Location:
    The Peoples Republic- Rocky Mountain Edition
    Currently, I'm waiting on a clutch basket holder that I ordered to show up (should be here on Friday).
    Also, found several another wonderful idiosyncratic elements of the bike that currently has me in a holding pattern. On top of the valve cover are two 'holes' which hold the spark plug wire/insulators. The size and diameter of these holes must be very, very important. I can almost see the engineers who designed these holes bent over their desks, calipers in hand, measuring down to the exact micron that these such holes must be.
    <img src="https://lh5.googleusercontent.com/-xjd3Y27048Q/UiXjgQZ-YPI/AAAAAAAACmw/WJJ5FmGTm9w/s640/BMW%2520motor%2520rebuild%2520-%252013.jpg" height="640" width="480" /></a>

    I know this because the 18mm spark plug socket I bought does not fit through them. Now, let it be known that a standard 18mm socket does fit through them. The difference between the two is about 1.5mm.
    <img src="https://lh6.googleusercontent.com/-HrpCPlXOl7o/UiXjiNP0IuI/AAAAAAAACm0/lBa38N86KvI/s640/BMW%2520motor%2520rebuild%2520-%252014.jpg" height="640" width="480" /></a>

    The Craftsman brand socket fits just fine, but I lost my 18mm deep socket this summer when my fender mounted tool kit decided to get a closer look at the Nevada sagebrush without telling me on this summers trip. So, I'm planning on going to the store to see if a non-spark plug specific, 18mm, deep socket will meet the exacting standards prescribed by BMW that will allow me to remove my own spark plugs.

    This weekend I also discovered that a standard depth 8mm hex head socket is not allowed access to the rear frame bolts. :nono It is not long enough to each inside the frame. One must have an extended 8mm hex head socket. Clearly I'm not man enough to work on my own bike.
    <img src="https://lh6.googleusercontent.com/-BAnFFIvY31g/UiXjqrmiYNI/AAAAAAAACnM/U8pX1ajKCTk/s640/BMW%2520motor%2520rebuild%2520-%252016.jpg" height="640" width="480" /></a>

    One thing that I did accomplish this weekend was the manufacturing of a TDC bolt. This is a M8 x 1.25 x 55mm bolt that fits into the bottom of the case to hold the crank at TDC. Rather than order one, I picked up a super strong M8 allen head bolt and attacked it with a file (somewhere in Germany an engineer just spit up in his pint glass).
    <img src="https://lh6.googleusercontent.com/-pIjA0ZmMx-Y/UiXjccNXYaI/AAAAAAAACmk/qlqzX2pFqjY/s640/BMW%2520motor%2520rebuild%2520-%252012.jpg" height="480" width="640" /></a>
    #10
  11. imeny

    imeny Been here awhile

    Joined:
    Aug 15, 2010
    Oddometer:
    132
    Location:
    Israel
    :lurk:lurk
    #11
  12. dakardad

    dakardad Not waiting for anyone

    Joined:
    May 22, 2006
    Oddometer:
    447
    Location:
    SLC/Boulder, Ut.
    Hummm,:eek1 I better check my shaft. I thought the sprocket was to soft when my sprocket started to wobble a bit.:muutt
    #12
  13. kubiak

    kubiak Long timer

    Joined:
    Nov 25, 2007
    Oddometer:
    4,837
    Location:
    madera california
    i had to check my splines after i saw this post too!
    #13
  14. tele-steve

    tele-steve ya' mon

    Joined:
    Sep 28, 2006
    Oddometer:
    267
    Location:
    The Peoples Republic- Rocky Mountain Edition
    So I picked up another 18mm deep socket that allowed me to remove the spark plugs. With one plug out, I could rotate the engine to find TDC. First I had to take off the valve cover.

    <img src="https://lh3.googleusercontent.com/-AX-DMoV4W4E/UidEGt_N-TI/AAAAAAAACpY/OhBds3LSmhc/s640/BMW%2520motor%2520rebuild%2520-%252024.jpg" height="480" width="640" /></a>

    That is a pretty easy job. The cover is plastic and the bolts have a flange on them to keep them from falling out all over the place. With access to the cams, it is easy to find TDC. Just rotate the engine with an 8mm allen key in the alternator rotor until the line on the cam sprocket is parallel to the head and the punched hole is straight up.

    <img src="https://lh4.googleusercontent.com/-nuNUwsOQZIw/UidEHcpr6CI/AAAAAAAACpk/qBWQEJeAtAs/s640/BMW%2520motor%2520rebuild%2520-%252025.jpg" height="480" width="640" /></a>

    With the cams at TDC, I screwed in my home made TDC locking bolt and locked the crank in place. Now it was onto removing the alternator rotor. I purchased a puller on line, but needed to remove the nut and lock washer. This is on there with 140Nm of torque, so it is no easy task to get off. I used a steel pipe as a cheater bar.

    <img src="https://lh4.googleusercontent.com/--XGXTDMjY4I/UidEEUxHdbI/AAAAAAAACpA/ry4RQbA-dII/s640/BMW%2520motor%2520rebuild%2520-%252018.jpg" height="480" width="640" /></a>

    With the nut loosened, but not completely off, I placed puller on the rotor and popped the rotor off the crankshaft. I left the bolt in place so the rotor would not pop all the way off and hit the floor. With the rotor loose and in place, I went back with the breaker bar and removed the nut the entire way.

    <img src="https://lh4.googleusercontent.com/-3B0en_J0pZE/UidEDmlCk_I/AAAAAAAACo0/IXDVaKqCoCE/s640/BMW%2520motor%2520rebuild%2520-%252019.jpg" height="480" width="640" /></a>

    <img src="https://lh4.googleusercontent.com/-hymPjhBpcpg/UidEECzQLdI/AAAAAAAACo8/oAeggsPim6o/s640/BMW%2520motor%2520rebuild%2520-%252020.jpg" height="640" width="480" /></a>

    <img src="https://lh4.googleusercontent.com/-LtK9YFue1P8/UidEGEpgT2I/AAAAAAAACpU/8btVq084qsY/s640/BMW%2520motor%2520rebuild%2520-%252023.jpg" height="480" width="640" /></a>

    The key on the crank was left on the alternator rotor. I'll deal with this when I have to put this back together.

    <img src="https://lh4.googleusercontent.com/-m0bqgSKvU1I/UidEFU1bcWI/AAAAAAAACpI/FAkTx5_h1MY/s640/BMW%2520motor%2520rebuild%2520-%252021.jpg" height="640" width="480" /></a>

    Now I'm just waiting on the clutch basket holder to arrive so I can finish taking out the clutch. Once that is done, the engine can come out of the frame.... maybe this weekend.
    #14
  15. imeny

    imeny Been here awhile

    Joined:
    Aug 15, 2010
    Oddometer:
    132
    Location:
    Israel
    Hi mate.

    I also want to remove the alternator nut, but afraid to broke the TDC bolt that locking the crank. The is a way to approve that the 140 NM force that you apply on the nut won't break the TDC bolt?


    Thanks

    Meny
    #15
  16. StevenD

    StevenD Hmmmm, dirt!

    Joined:
    Aug 3, 2005
    Oddometer:
    1,272
    Location:
    Holland, Amserdammed
    Air impact wrench and no lock is safe to take it off as that takes a lot more than 140nm. On with 140 should be no issue.
    #16
  17. mbrick

    mbrick Been here awhile

    Joined:
    Feb 22, 2012
    Oddometer:
    176
    Location:
    West coast red sticker territory
    I agree, the TDC lock bolt is probably not a great idea to hold it while loosening that nut.

    I would suggest putting the bike in gear and using the rear brake to hold it. Then use an impact wrench.

    I've also stuffed a rag between the main gear and clutch basket gear to lock the crank and use a big breaker bar. Both have worked.
    #17
  18. Homerb

    Homerb Been here awhile

    Joined:
    Jun 24, 2011
    Oddometer:
    577
    Location:
    Toukley NSW Australia
    Ive got a jar of old pennys l use to lock up the gears on my honda. Theyre soft enough not to damage the gears. And be careful not to lose the woodruff key between the flywheel and crankshaft. The little buggers have a habit of dissapearing when you get to reassembly.
    #18
  19. Kawidad

    Kawidad Long timer

    Joined:
    Jul 9, 2005
    Oddometer:
    5,642
    Location:
    Central Coast, Cal
    I'm in too. :lurk
    #19
  20. foggy50361

    foggy50361 Adventurer

    Joined:
    Jul 18, 2013
    Oddometer:
    74
    Location:
    God's back garden, Wales
    This is proper Heath Robinson.

    I to am In!:evil
    #20