My R1200GSA Step-by-Step Gearbox Removal Process

[JimVonBaden]

Originally Posted by bigjohn66

About the top bolt "special tool", what's the bolt diameter and length needed? Thanks!

I have a set at home, I'll measure them tonight if no one else chimes in.

IMHO they should be a little longer than the ones shown here.

Jim

[farmerger]

Originally Posted by JimVonBaden

I have a set at home, I'll measure them tonight if no one else chimes in.

IMHO they should be a little longer than the ones shown here.

Jim

Its an M10x40, so 10mm diameter 40mm long.

Jim, not sure what you mean that they should be a little longer? I bought a 40mm and cut the head and a bit of the threads off, came out to be around 35 mm long.

[JimVonBaden]

Here is a photo of mine:



As you can see, substantially longer, and my pictorial says 80mm, so I am guessing that was correct. Might be different for an R1200, and I used mine on the bottom, but more length is good IMHO.


With the trans in place.


If you look hard you can see them here.

1150 pictorial: http://www.bmwbmw.org/forums/viewtop...it=spline+lube

Jim

[farmerger]

Jim,

I think these are two completely different applications. Yours look like they act as guide pins for aligning the transmission to the engine. The ones I was referring to replace the top bolts that connect the rear frame to the sides of the engine. You don't slide anything over them, but they need to sit flush once inserted so that you can pull the eyelet from the rear frame past them.

[JimVonBaden]

Originally Posted by farmerger

Jim,

I think these are two completely different applications. Yours look like they act as guide pins for aligning the transmission to the engine. The ones I was referring to replace the top bolts that connect the rear frame to the sides of the engine. You don't slide anything over them, but they need to sit flush once inserted so that you can pull the eyelet from the rear frame past them.

Ahhhh, sorry, you are correct!

Sorry for the confusion!

Jim

[jdub]

farmerger - Thanks for posting the additional photos that continue to add good info here. I did my R1100S gearbox removal solo like you did on your GS, and I vowed not to attempt that again during the subframe splitting and remating phases. Like me with the S, you probably made up a few new cuss words along the way.

And thanks to all the other contributors as well!

[jdub]

Originally Posted by Eagleavn

Now his ego will never be the same.....

The Eagle

PS....nice job...You want to do my 1100GS.....

Hey, you know I'll work for SB coffee or single malt Scotch. My rates for doing your GS clutch splines should keep me supplied for at least a year or two.

[Usmc1968]

Excellent info!!
Thanks for posting it

[bob393]

This took a lot of effort! Thank you for enlightening us.

[wjherrick]

Booked Marked for future reading!

Bill in OR

[AussieKen]

Great work mate. Excellent explanations. I might get stuck into mine very soon as I know the splines would be dry at 100,000K's. Thank you in advance.

Cheers

Aussie Ken

[bigjohn66]

Shouldn't this be moved into the HOW? I forsee a demand for this thread down the road as hexheads start getting higher and higher miles on them. It's very well laid out and has additional info, such as the special support studs dimensions, that make it a great candidate for inclusion.

[cnj3]

When you reinstall the transmission, do you need to do anything special to align the input shaft splines?

[The Other JC]

Originally Posted by cnj3

When you reinstall the transmission, do you need to do anything special to align the input shaft splines?

So long as you have not taken the clutch apart, the gearbox will slide straight back into position regarding input spline to clutch. If you have taken the clutch apart you will need to centre the friction disk, slide the gearbox back on to centre the friction disk, then do up the clutch housing bolt to hold the disk in place, remove the gearbox, and complete the clutch housing bolting with correct torque. Then slide the gearbox back on. (or use BMW centering tool or similar!)

Either way, leave the gearbox in gear and rotate the output spline to turn the input spline to line up with the friction disk spline grooves if required.

And don't forget to make the a couple of studs to replace the bolts for the gearbox to slide on when you remove and install the gearbox. Helps in holding the gearbox level when getting the input splines lined up, and same removing level.

[jdub]

Originally Posted by cnj3

When you reinstall the transmission, do you need to do anything special to align the input shaft splines?

No, as clarified by The Other JC. Once you mate the male (gearbox shaft) and female (clutch hub) splines together, just slide the gearbox straight forward and it will engage with and be positioned by the alignment dowels on the engine case. Easy then to just keep a hand on the gearbox while you install the bolts that secure the gearbox to the engine case, and I saw no need to use temporary gearbox guide studs or pins.

Unlike on R11x0 bikes where the rear subframe is pivoted upward during this project and you have to work around it, it's easy to eyeball the spline engagement from the top on an R1200 with the subframe fully out of the way. This also makes handling of the gearbox much easier.