Go Back   ADVrider > Bikes > GSpot > GS Boxers
User Name
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
Old 01-30-2011, 01:06 PM   #1
jdub OP
Dawg bytes reel gud
jdub's Avatar
Joined: Jan 2004
Location: S. Central PA
Oddometer: 1,900
My R1200GSA Step-by-Step Gearbox Removal Process

With 68,170 miles now on my '07 R1200GSA and some time on my hands this winter, I decided to give my bike a Christmas present in the form of a clutch spline inspection and lube. Having done this before on my R1100RS (when I had to replace the clutch at 30k miles), on my R1100S at 42k miles and when helping my buddy do the same on his R1150GSA (92k miles), I knew the Hexhead would be a bit different as each of the others had been.

Before diving in, I searched many, many threads in GSpot for text and pictures on procedures. I found lots of scattered references to things like "remove wiring harness from the subframe", but no real detail as to what all was really involved to achieve that result. Loving this type of challenge, I therefore gathered all of the various references, pointers and pictures I could find and set out to document my own process for splitting the bike and removing the gearbox for spline access. With the help of my son, home for the holidays from college and too slow to come up with any excuses like how busy he was, we dove in.

Below are the pictures I took along the way, as are the step-by-step procedures I used with a bit of trial-and-error thrown in. No real errors though, just things I noted along the way as "I'll do that this way instead next time". Since I was unable to find such detailed procedures prior to my experience, I'm providing mine here in the interest of helping out fellow inmates who are interested in taking the same plunge. As the saying goes, "There's more than one way to skin a cat", and I have little doubt that there are short-cuts or maybe better ways of achieving the same end result. Hopefully those who read this can share those notes so that we can all get smarter.

Here goes:
1. Place bike on centerstand, remove the seats and battery (negative lead first, of course).

2. Remove all body work around the fuel tank, disconnect drain lines at tank, fuel line QDs and wiring plugs, remove mount bolt on each side (hex head bolts, go figure with all the other Torx fasteners on the bike) and remove the tank. You’ll now thank yourself if your GSA tank is low on fuel.

3. Remove the bolts with spacers (two on each side) on sides of luggage rack; these bolts attach to the subframe.

4. With the luggage rack still attached to it, remove the rear silver plastic cover above the rear fender (5 top screws plus the smaller screw just outboard of the seat lock mechanism).

Note highlighted screw at seat lock mechanism:

5. With the cover now removed for access, disconnect the rear wiring harness at the plug just in front of the taillight assembly, cut all wiring harness tie-wraps on the rear fender, remove the two nuts and washers for the right side of the seat lock mechanism and then slip the wiring harness and diagnostic plug under the lock mechanism so the wires are free of the subframe.

Rear wiring harness plug just forward of taillight:

Right side of seat lock mechanism, remove nuts, raise and slide wiring harness under:

6. Disconnect wiring harness lead from the aux plug socket and lift the whole wiring harness, including both battery leads, free of the rear subframe. Remove the two screws holding the harness's plastic channel to the subframe, so harness stays in the channel (to left of air box).

Left front seat bracket removed to ease wire harness separation from subframe, harness lifted forward:

7. Remove the muffler by loosening the lower clamp forward of the muffler and remove the single bolt attach point above muffler, then wiggle the muffler off the exhaust pipe. Remove the two bolts for the clamp around the catalytic converter, then wiggle the clamp aft off its mount point and clear of the bike.

8. Where they screw into the ABS unit, disconnect the two rear brake lines and cap/plug the lines and the corresponding ABS unit receptacle holes. Although I was ready for it with plenty of rags, there was virtually no brake fluid leakage or loss when the lines were broken loose and removed here. These lines will stay with the rear subframe; nothing else needs done with the rear brake system at this time.

Fingers pointing to two rear brake lines to be removed at ABS unit:

9. By squeezing their ends with pliers and prying the ends a bit with a screwdriver, I popped loose and removed the metal band clamps at the front and rear of each throttle body where they attach to their respective manifolds. I was more than happy to toss these OEM clamps into the trash, and I replaced them with the much more user friendly worm-type hose clamps upon reassembly.

10. Cut and remove the tie-wraps under the throttle bodies, then move the left throttle body free of the manifolds so you can access one of the rear subframe attach bolts. This is a very tight fit and takes some wiggling. The right TB can be wiggled loose and removed as the subframe is moved rearward.

11. Remove the clutch slave cylinder’s two bolts that attach it to the gearbox rear face and move the unit aside with the fluid line still attached. NOTE: These bolts heads on my bike had lots of dirt inside them, keeping the TORX bit initially from fully seating which could have lead to a stripped out bolt head had I not noticed. I used a very fine dental pick to clean out all of the dirt, and then tapped lightly on the TORX bit with a small hammer to ensure it was fully seated before breaking the bolts loose. The bolts were much tighter than they should have been given their torque value, so beware.

12. Remove the plastic cover over the starter and wrestle it out of the frame. I noticed on a friend’s ’09 GS that this cover is not used anymore, and after wrestling it out I debated even reinstalling it again (but I did). Disconnect the starter hot wire and the small wire connector, and then remove the two starter mount bolts and the starter itself.

13. Where it comes out of the gearbox, mark the end of shift shaft at the linkage attachment split line, the remove the linkage bolt and wiggle it off the shaft. You’ll use this mark during reassembly to ensure proper lever position with no trial and error to get it right.

14. At the rear of the left cylinder, remove the two bolts for the air box breather hose and remove it while taking note of the sealing o-ring for reassembly.

15. At front left of air box, release the catch and slide the throttle cable junction box assembly to the left and away from the air box.

16. Remove the clamp at the front of the rubber accordion boot at the swingarm/gearbox interface. It is very tight with little room to work, but slide the boot back and use a large/wide bladed screwdriver to gently pry the very front of the driveshaft U-joint off of the gearbox output shaft spline retaining circlip. The splines do not need to be fully disengaged here, just popped loose of the retaining circlip, so ” or so rearward is plenty. The driveshaft will move rearward with the subframe.

17. Remove the single subframe/gearbox mount bolt just underneath the air box (accessed from the right side of the bike).

18. Double check all tie-wraps are cut as needed and that all wires are free and are not routed through any rear subframe tubes.

19. Remove GSA lower crash bar on each side (loosen the big bolt at the lower attach point to the engine, remove the screw and the bolt with the half-clamp it holds at the lower/upper crash bar junction just above where the header pipe exits each cylinder, slide each crash bar clear).

20. Because I don’t own a ‘proper’ motorcycle engine lift, I laid a four foot long 2x4 board on the floor under the engine but perpendicular to the longitudinal axis of the bike. I then placed my floor jack on top of this board to hold it down and in place and pumped up the jack until it touched the skidplate (with a piece of board between the two for weight distribution). I ran a looped tie down strap around each cylinder head with the bottom of each loop under the board at a point directly beneath, then I drew each strap tight. I pumped up the jack a bit more, tightening the straps further and balancing the front half of the bike side-to-side. A board was placed under the rear tire to keep both halves the same height while separating (keep centerstand deployed).

21. Going side-to-side, I loosened and then removed the three bolts (two high, one low) on each side of the bike at the rear subframe attach points.

22. Ensuring that the front half of the bike is supported at the proper height with the jack, and using a helper at the rear of the bike to pull and wiggle, slowly move the rear subframe rearward ensuring that nothing is binding or holding the halves. The front of the rear subframe remains supported by the centerstand during this process. Once free, move the rear subframe away. We just wheeled mine into another room, placed a few barbell plates on the centerstand tab and it remained perfectly stabilized.

Ready to split:

Bike split (with my son wondering what his old man has gotten him into again):

Rear subframe resting peacefully, note weights on centerstand tab stabilizing everything and red caps keeping brake line ends sealed:

23. Grab the end of the clutch push rod extending through the center of the gearbox input shaft where the slave cylinder attaches, and withdrawal it to the rear. On my RS, this rod was stuck at the front to the clutch diaphragm spring and took some persuasion to break free and slide rearward, but fortunately came right off on the GSA. Remove the small bolt at the center rear of the plastic cover on top of the gearbox (I just left the cover in place).

Picture of my engine support rig. Note end of clutch push rod is visible protruding from the rear of the gearbox:

24. Remove the three remaining gearbox attach bolts. My gearbox was stuck fast to the engine rear case due to some not yet visible corrosion at the two guide dowel alignment points (at upper left and lower right gear box attach bolts). After quite a bit of not so subtle persuasion with a rubber mallet and board, and judicious use of a heavy duty putty knife gently tapped into varying points around the perimeter of the split line as a thin wedge, the gearbox came free from the engine and was lifted to my work bench. Using Scotchbrite, I cleaned up the small bit of corrosion on the alignment dowels and applied a thin film of grease to them, hoping to avoid similar separation problems the next time.

Gearbox on work bench, front side with dry input shaft splines visible:

Exposed clutch assembly, plastic cover still in place on top and counterbalancer visible below:

25. My clutch splines were completely dry with a bit of reddish rust present, but both the input shaft’s male splines and the clutch’s female splines cleaned up easily and beautifully. I applied a light film of moly grease to the male splines, and reinstalled the gearbox. I then applied a film of moly grease to the gearbox output splines. My first experience with it, but I used GD525 moly grease from Guard Dog Lubricants (, based upon a recommendation I recently read from someone who has many years of experience and experimentation with spline lubes on BMWs. Careful not to use too much lube on the clutch/input splines, as excess can be thrown onto the clutch friction material by centrifigal force and mess things up a bit.

Before and after pics of male and female splines:

26. Reinstall the gearbox.

27. Prior to re-mating the subframe, I withdrew the driveshaft from the front of the swingarm and set it aside. Due to the very minimal amount of clearance available at the front swingarm boot when the subframe is installed, I expected a very difficult time reseating the front U-joint on the gearbox output shaft retaining circlip and planned an alternate method of installation. I fought (and fought and fought) the same issue when re-mating the subframe and driveshaft on my R1100S years ago, and decided to learn from that experience.

28. Re-assembly, all the way up through the body work, was all pretty much in reverse order. Have lots and lots of new tie-wraps handy, and of course torque all bolts and nuts to their proper torque values.

29. Once everything else was installed and attached, I removed the final drive drain plug and pivoted the FD down for draining (my FD is an early ’07, pre-drain plug on the bottom). I inserted the driveshaft from the rear of the swingarm, and attempted to guide the front U-joint splines up and onto the gearbox output splines. Due to the minimal clearance at the boot and the u-joint angle, I had a difficult time getting the front of the driveshaft to line up and engage with the gearbox output shaft so I removed the rear shock lower mount bolt and pivoted the shock aft. This allowed me to then pivot the swingarm upward and parallel with the output shaft, and then the driveshaft splines slid on easily. Once the splines were engaged all the way forward, I gave the rear of the driveshaft a rubber mallet rap and ensured that the front retaining circlip was fully engaged. I lubed the rear driveshaft splines and re-engaged them with the FD splines while pivoting the FD back into position. The FD was then reserviced with 180cc of fresh gear oil. NOTE: After this bit of trial and error, which lead to what I now believe was some unnecessary effort, next time I’ll keep the driveshaft in the swingarm and will just engage the splines as the rear subframe is being re-mated. I’ll then just have to pry the front of the driveshaft forward and engage the spline retaining circlip, then refit the boot and secure it with a tie-wrap.

30. Bleed the rear brake system due to the disconnected ABS lines (mine was due for the bi-annual fluid change anyhow), and the project is done.

Back together again:

Have fun!
Current: 2014 R1200GSW & 2007 DR650

jdub screwed with this post 01-31-2011 at 08:16 AM
jdub is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

Times are GMT -7.   It's 11:08 AM.

Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2015