G-Spot-Michael
Registered user
Hello all, new here, owned a ~50k Mi 2009 BMW 1200GS, K25 or more like a 2008 (0303,0313 according to real OEM vin).
Recently noticed weeping oil from the FD case, behind the flange for the brake disk. Went to change the seal and found the inner bearing coming apart. Kept riding it and just flushing fluid every week. It seemed to leak down from the spec of ~200 to 150ML very fast (~10mi) then weep but loose only 1-5ml every 100+miles after that. Lucky for me I stay away from the rear brake...
This bought me time to limp the bike to and from work while I bought a used final drive case from a 2010 GS and rebuild it...
As I went through this, I learned what the stampings on the final drive case mean, what the spline count on the gearbox side and FD side are, what differentiates the ABS on these bikes vs the earlier gens, and I changed all the bearings and seals, minus the pinion shaft stackup, as I was doing this in my kitchen, in a studio flat...with an Amazon press, and didn't see anything wrong with the pinon side...
I got all my parts off of Motoworks BMW. I found the BMW manual for the non-vented case which I used as a rule of thumb and will link it here if it embeds: https://archive.org/details/rear-be...oad, Borrow, and Streaming : Internet Archive
Attached are photos, diagrams, and if anybody has questions about their bikes FD that they want answered please shoot them across to me!
This was the first attempt at changing the seal.
Don't let anybody fool you, this flange is F-ING TIGHT, and wont move with a torch and puller alone. I had to sacrifice lug bolts and a 3 jawed puller to get it off, and even then it was a fight...
BMW manual says don't let it get past 100c, lies, get it smoking.
When I did eventually get that apart, and yanked the seal out I found bearing #9 coming apart. The oil had been dark since I got the bike but I never saw any metal and wasn't overly concerned. It still spun smooth, but the cage had completely come apart...
Unfortunately to get to this, its the box off the bike, split the case, and if you're going that far, may as well do everything... As I know the higher mileage bikes like to eat ring gear bearings.
I decided to buy a used FD off of Ebay, from a similar mileage 2010 bike, and this entered the "What the hell differentiates these FD's from one another, can I get a 2010 bike one or do I need same year etc"
On your FD you'll have some things to consider: Vented or non vented case, Integral or non integral ABS, Spline count on the driveshaft and gear ratio. The gear ratio can be found here on the case
Mine is listed as 32/11.
The next thing is spline count, which i found hard to get photos online of mine. I dropped my FD down and counted the splines. On the FD side you should have 20.
On the Later bikes I believe 2011+ have 22, but im unsure.
Recently noticed weeping oil from the FD case, behind the flange for the brake disk. Went to change the seal and found the inner bearing coming apart. Kept riding it and just flushing fluid every week. It seemed to leak down from the spec of ~200 to 150ML very fast (~10mi) then weep but loose only 1-5ml every 100+miles after that. Lucky for me I stay away from the rear brake...
This bought me time to limp the bike to and from work while I bought a used final drive case from a 2010 GS and rebuild it...
As I went through this, I learned what the stampings on the final drive case mean, what the spline count on the gearbox side and FD side are, what differentiates the ABS on these bikes vs the earlier gens, and I changed all the bearings and seals, minus the pinion shaft stackup, as I was doing this in my kitchen, in a studio flat...with an Amazon press, and didn't see anything wrong with the pinon side...
I got all my parts off of Motoworks BMW. I found the BMW manual for the non-vented case which I used as a rule of thumb and will link it here if it embeds: https://archive.org/details/rear-be...oad, Borrow, and Streaming : Internet Archive
Attached are photos, diagrams, and if anybody has questions about their bikes FD that they want answered please shoot them across to me!
This was the first attempt at changing the seal.
Don't let anybody fool you, this flange is F-ING TIGHT, and wont move with a torch and puller alone. I had to sacrifice lug bolts and a 3 jawed puller to get it off, and even then it was a fight...
BMW manual says don't let it get past 100c, lies, get it smoking.
When I did eventually get that apart, and yanked the seal out I found bearing #9 coming apart. The oil had been dark since I got the bike but I never saw any metal and wasn't overly concerned. It still spun smooth, but the cage had completely come apart...
Unfortunately to get to this, its the box off the bike, split the case, and if you're going that far, may as well do everything... As I know the higher mileage bikes like to eat ring gear bearings.
I decided to buy a used FD off of Ebay, from a similar mileage 2010 bike, and this entered the "What the hell differentiates these FD's from one another, can I get a 2010 bike one or do I need same year etc"
On your FD you'll have some things to consider: Vented or non vented case, Integral or non integral ABS, Spline count on the driveshaft and gear ratio. The gear ratio can be found here on the case
Mine is listed as 32/11.
The next thing is spline count, which i found hard to get photos online of mine. I dropped my FD down and counted the splines. On the FD side you should have 20.
On the Later bikes I believe 2011+ have 22, but im unsure.
