BMW R1100GS: Final Drive Splines Lube

The below repairs, replacements, and what-not have all been done by me on my 1995 R1100GS. This procedure applies to all R850/1100/1150 type BMW motorcycles with or without ABS. Do not attempt any of these procedures unless you're confident in your skills - however limited - as a shade-tree mechanic. Don't send me hate mail if you mess something up!!

Lubricating Final Drive Splines

Note: You'd normally think the brake disc would be connected to the rear wheel - but this is not always so. On some R850 & 1100 bikes, the rear disc brake is actually connected to the DRIVE, not the wheel - be aware that brake pads and brake dust can be VERY harmful to your health - don't inhale brake dust, don't put brake-dirtied fingers in or near your mouth or nose, and clean your hands thoroughly when you're done.

1. This is the only real supply you need - Honda Moly 60 Paste. This molybdenum-based lubricant is the best material for this application. It is called paste for a reason though - it will stick to anything and everything it comes into contact with, so wear gloves and try not to get it on your clothing!
2. Put the bike up on its center stand and SECURE i t by running a tie-down through the front wheel and around the center stand legs .
3. Remove both side cases.
4. Support bike (if necessary) so the rear wheel is completely off the ground.
5. Remove the rear mud guard (4, 5mm hex).
6. Remove and secure the rear brake caliper (8mm hex). You can see I zip-tied it to the right passenger footpeg/side case support. Once the caliper is removed, do not depress the rear brake lever.
7. Remove the rear wheel and set it aside, being careful not to rest its weight on the spokes (or brake disc, if attached like it is on the GS). (17mm hex)
8. Detach the ABS sensor (if present) from the final drive (T25 Torx). Be extremely careful not to lose or bend the spacers between the sensor mount and the final drive - there can be several of them and they are very thin and fragile!. Secure it away from the final drive.
9. Remove the torque arm from the bottom of the final drive (16mm socket, 16mm wrench).
10. Support the final drive unit with something - a block of wood, cinder block, jack, whatever. Don't just let it hang loose.
11. Heat the lock nut and inner (left) pivot pin (pictured) until spit sizzles off them quickly.
12. Loosen and remove the lock nut (30mm socket).
13. Remove the pivot pin (12mm hex).
14. Remove both final drive boot o-clips (thin flathead screwdriver).
15. Heat the outer (right) pivot pin (not pictured) until spit sizzles off it quickly.
16. Remove the outer pivot pin (12mm hex). Be sure the bearing comes out with the pin - if it does not, reach in and remove it. You should not be able to remove the bearing race from the swingarm.

At this point, you should be able to easily remove the entire final drive assembly from the end of the swingarm. Fold back the boot and gently pull until it comes loose. Set the entire unit aside - REMEMBER TO KEEP THE UNIT UPRIGHT if it is still full of gear oil (you do not have to drain the final drive of its gear oil to perform this maintenance task).

I like to put the torque arm bolt back in the final drive as well as two lug bolts to aid in handling the detached final drive.

17. Inspect all parts removed from the swingarm and final drive. If any of them are damaged, pitted, or otherwise unacceptable, replace them per the following list (applies to '95-99 R1100GS specifically, may apply to other models - check the parts fiche!):
  • Torque arm bolt (M10x55-8.8ZNS) - 07 11 9 900 139
  • Torque arm bolt nut, self-locking (M10) - 07 12 9 964 676
  • Inner (left) pivot pin - 33 17 2 311 074
  • Pivot pin lock nut - 33 17 2 312 217
  • Outer (right) pivot pin - 33 17 2 310 890
  • Rubber boot - 33 17 1 452 504
  • Large o-clamp (tension strap) - 33 17 2 335 120
  • Small o-clamp - 33 17 1 458 197
  • bearings - internet wisdom (aka ADV Rider) recommends this aftermarket set of bearings.

18. Top pic here is the inner (left) pivot pin, or adjustable pivot pin, with its lock nut.
19. Bottom pic here is the outer (right) pivot pin, or fixed pivot pin, with its bearing.
20. Clean all loc-tite from the threads of both pivot pins and the lock nut.
21. Clean all surface lubricants from the smooth surfaces of the pivot pins and the bearings. Note that the inner pivot pin's bearing is still in the final drive.

22. Clean all loc-tite from the threads of both pivot pin threads in the swingarm.

Note: you may need to use the heat gun on either (or both) the pivot pins, lock nut, and swingarm to get the left-behind loc-tite loosened up enough to scrape it out with the dental picks. Be careful, the pins especially retain heat for a long time!. Be methodical, take your time, and get every scrap of dried-up loc-tite out of all the threads.

23. Clean all surface lubricant from all surfaces on the spline mating surfaces - the drive shaft inside the swingarm and the universal joint sticking out of the final drive.

As you can see in these pictures, my splines were nearly completely dry but are in good condition. That means I did this maintenance after it really should have been done, but before any damage occurred.

BMW recommends this maintenance task at infrequent intervals (40,000 miles), but my bike only had about 11,500 miles on it at the time I did this maintenance (25 May 08). Time takes its toll too, so if you buy an older bike and the previous owner has no record of having the splines lubed, you should think about doing this task or having it done.

24. Using the chopstick (or other applicator), apply a thick coat of the Honda Moly 60 paste to the inner and outer surfaces of the splines - both on the driveshaft and on the mating surfaces on the universal joint sticking out of the final drive.
25. Apply a thin layer of the Honda Moly 60 to the smooth surfaces of the bearings and pivot pins, taking extreme care not to get the Moly paste on any threaded surfaces.
26. Reinstallation is the reverse of removal!
27. First reconnect the final drive to the driveshaft. In this process, using a log flat-bladed screwdriver can help maneuver the driveshaft into place and angle it so you can slide the final drive home. It definitely takes some patience and fiddling. One thing that helps is having two lug bolts in the final drive and putting the bike in gear so the driveshaft cannot move much. Once you get the smooth part of the final drive universal joint shaft inside the driveshaft, remove the screwdriver and, using the lug bolts to jiggle the FD shaft back and forth, get it seated inside the driveshaft - then just gently ram it home. You should be able to see the bearing surfaces of the final drive through the holes in the swingarm.

28. Put a wide line of fresh loc-tite on the outer (fixed/right) pivot pin and reinstall it until it is flush with the swingarm.
29. Torque the outer pivot pin to 150N-m.
30. Put a wide line of fresh loc-tite on the inner (adjustable/left) pivot pin and reinstall it by hand until it stops. Use the 12mm hex socket to tighten it slightly.
31. Torque the inner pivot pin to 7N-m.
32. Install the lock nut on the inner pivot pin, ensuring that there is fresh loc-tite on the threads of the pin.
33. Torque the lock nut to 150N-m.
34. Reattach the final drive boot and secure both o-clamps.
35. Reattach the torque arm and torque its bolt/nut to 22N-M (or very hand tight).
36. Reinstall the ABS sensor, being extremely careful to install the spacers gently and properly. (Remember that the spacers go between the base of the sensor mount and the final drive.) Tighten the Torx bolt to firmly hand tight.
37. Install the rear wheel. Initial torque on the lug bolts is 50N-m (seriously hand tight); torque the bolts in a criss-cross pattern to 105N-m and remember to check them in a few days.
38. Reattach the rear brake, being careful not to twist the brake line and ABS wiring. Torque the brake bolts to 40N-m.
39. Visually check your work to make sure you have no extra parts lying around.
40. SLOWLY test ride the motorcycle.

41. Clean up! Be sure to properly dispose of anything that touched the Moly paste - I like to wrap it in another bag and put that in the trash too. That stuff is nasty but it works!