2018 GS final drive issues

[hawkster]

I bought a 2018 R1200GS, mileage about 58,000 miles. What seems to be this model's record with the notorious final drive failures?

 

[pglaves]

I bought a 2018 R1200GS, mileage about 58,000 miles. What seems to be this model's record with the notorious final drive failures?

Not entirely, but mostly non-existent. The most common issue mislabeled as a "failure" is an outer seal that may seep. It costs only a few dollars and can be replaced in 5 or 10 minutes.

 

[Boxflyer]

Final drive issues pretty much stopped after 2010...few and far between.
I wouldn't worry about the Final Drive, it's really good now.

Before 2010, the "big bearing" (crown gear side) was not on the gear side of the case housing running in oil, but instead, simply a double sided sealed bearing behind the wheel lug flange with a normal chevron seal to keep out water and dirt.
In the 2010 and newer final drives, both the "big" bearing and the roller bearing side of the crown gear shaft are bathed in the 75-90 gear oil. Also added in 2010 is a breather for the expansion of air within the gear case.

Here's my 2008RT final drive "big bearing" at 32k with a failure.

Here's a K52 showing that the bearing is on the inside of the seal (#3) and inside the oil.

Here's a K26 (2010) showing how the bearing is on the outside of the seal (#7), and outside the oil as well.

 

[cap]

On the other hand…

There are some potential trouble spots for your bike. One of them is the splined interface between the driveshaft and the final drive. This can become rusted and difficult to separate. Easy to check. See Boxflyer’s videos for the 12k service.

And while you are dropping your final drive to inspect it, take a look at the flapper in the exhaust manifold. It can seize. Fortunately, if it fails, it typically fails in the open position, which shouldn’t cause major problems but might throw a code.

Cap

 

[ramble]

Cap......Got a pic of this flapper valve?

 

[Boxflyer]

Sorry for butting in here Cap...

ramble:
Here's a view of the way the early style exhaust flap works.
This video is from my YouTube 12k Service Series
https://youtu.be/c1_1gPRA274?t=908

Here are some pics of the exhaust header.

This may have changed to a random check, not every time, after a software update from the dealer or a newer build bike.

I had one seize on the shaft while under warranty on my 2016RT.
The dealer replaced the entire header/cat/flap as a single unit as there is no way to individually replace the flap.

 

[pglaves]

I had one seize on the shaft while under warranty on my 2016RT.
The dealer replaced the entire header/cat/flap as a single unit as there is no way to individually replace the flap.

Now that is not what you call excellence in design.

 

[88bmwjeff]

Now that is not what you call excellence in design.

It certainly wasn't designed for serviceability. I don't understand why they didn't make that flap more serviceable. It seems way overkill to have to replace the headers, cat and flap just to replace a faulty flap. Oh well, not much I can do about it. Is there an annual service one can do to limit the possibility of that flap freezing? Or, do we all just roll the dice and hope for the best?

 

[pglaves]

I would assume that some type of high-heat resistant lubricant would be a good idea. Copper anti-sieze comes to mind but I am clueless how it could be applied to get where it needs to go.

My "design" would have included it as a canister type bolt-in, removable device. Or better yet figure out how not to need it at all.

 

[motodan]

It certainly wasn't designed for serviceability. I don't understand why they didn't make that flap more serviceable. It seems way overkill to have to replace the headers, cat and flap just to replace a faulty flap. Oh well, not much I can do about it. Is there an annual service one can do to limit the possibility of that flap freezing? Or, do we all just roll the dice and hope for the best?

They roll…