Unusual clutch activity on R1200GSW

I have a 2013 R1200GSW. For over a year I have noticed that when I slow to a stop, as I come to a near crawl with the clutch lever fully pulled in and the bike in 1st gear, the drive train will pulse a few times as if the clutch is lugging on the engine. The RPMs do not slow, the bike does not stall, but it clearly feels as if the clutch is not fully disengaged. I took it to a BMW dealer near my house (whose service manager is not as knowledgeable as I would like) and after driving it he did not feel the sensation. You can also reproduce the sensation if you are at a full stop, lightly let the clutch lever out until the friction zone engages, then pull the lever back in. This results in the same 2-3 pulses as if the flywheel is dragging against the clutch mechanism in some way.

I have JVB's DVD stating the mineral oil in the hydraulic clutch reservoir on these bikes frequently has been over-serviced and some mineral oil may need to be removed. Also I have read in MOA or BMW Rider magazine that the oil refill amount should be 3.8L and not 4L. Could too much mineral oil in the clutch reservoir or too much oil in the sump cause this sensation? Am I going to put excessive wear on my clutch plates? Why can't the moron at BMW feel the problem as I described it?

Anyone else noticed this with their clutch?

David

No answer from me, a question of what oil viscosity in engine?

The Wedge K12S's , before they changed the recommended viscosity , clutch action was wonky at times like you describe.

Not sure of the viscosity as I'm at work now. But it is the recommended viscosity in the owners manual.

dclarkfs1 said:

I have a 2013 R1200GSW. For over a year I have noticed that when I slow to a stop, as I come to a near crawl with the clutch lever fully pulled in and the bike in 1st gear, the drive train will pulse a few times as if the clutch is lugging on the engine. The RPMs do not slow, the bike does not stall, but it clearly feels as if the clutch is not fully disengaged. I took it to a BMW dealer near my house (whose service manager is not as knowledgeable as I would like) and after driving it he did not feel the sensation. You can also reproduce the sensation if you are at a full stop, lightly let the clutch lever out until the friction zone engages, then pull the lever back in. This results in the same 2-3 pulses as if the flywheel is dragging against the clutch mechanism in some way.

I have JVB's DVD stating the mineral oil in the hydraulic clutch reservoir on these bikes frequently has been over-serviced and some mineral oil may need to be removed. Also I have read in MOA or BMW Rider magazine that the oil refill amount should be 3.8L and not 4L. Could too much mineral oil in the clutch reservoir or too much oil in the sump cause this sensation? Am I going to put excessive wear on my clutch plates? Why can't the moron at BMW feel the problem as I described it?

Anyone else noticed this with their clutch?

David

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Hi David,

You are mixing fluids here. The mineral oil in the clutch is about 4 ounces. The overfill, especially on a 2013, is a teaspoon or two only.

The engine oil is 4.3 liters. I add 4 liters and am dead on for engine oil.

Jim

Thanks, Mr VanBaden. Let me thank you for the DVD you sent me. So far I have saved hundreds of dollars doing routine mechanical items on my BMW. Although you make changing the shims look easy, I am so far happy to find my clearances still in spec.

It amazes me that I ordered a shop manual on my GS wet head when I bought it 2 years ago and there is still nothing other than forums and your excellent DVD to help us do simple but expensive maintenance on our bikes.

Your DVD made it clear that the clutch reservoir is mineral oil and to not use regular DOT brake fluids. It also mentioned that many times the reservoir is over serviced and may require removal of a slight amount of fluid.

I really should do this. It is a simple "rule out" fora cause of my clutch sensation.

I am not a total idiot. I have driven many bikes over many hundreds of thousands of miles on 3 continents. I have not experienced this bouncing of a drive train when the clutch is supposed to be completely disengaged. This is the first hydraulic clutch bike I have owned.

Naturally this fact makes me wonder if the bouncing is normal for a hydraulic clutch and how can a hydraulic clutch be adjusted, if even.

The pitiful part is a service manager who "can't reproduce the problem."
He did record the problem so that BMW may see a common problem and issue a recall.

Whatever. I just want the pulsations to cease when I roll to a stop.

That sounds like an annoying problem. I am pretty sensitive myself to little shakes and rattles when driving/riding vehicles and I've noticed that others don't always notice those things. I don't know the solution to your problem but that is not a normal sensation for all hydraulic clutches. I ride a 2002 RT and a 2014 Electra Glide, both with hydraulic clutches, and neither one has any pulsing like you describe. Comparing the hydraulic Harley clutch to the cable ones, the friction zone is smaller and so engages and disengages more abruptly but that is the only difference I notice when riding it. The hydro clutch on the Harley is not adjustable and I don't believe the RT one is either.

I wonder if the pulsing has something to do with the centrifigally assisted clutch on the wet heads? I have not ridden one but from reviews I understand that the clutch engagement feels dramatically different at different engine RPMs. Maybe disengagement has a different feel as well?

Just postulating here, but it sounds like you're looking at TWO different - but definitely related - issues:

1) Wet clutches will have more drag than dry clutches if not "properly" adjusted, just due to hydraulic linking (drag). Even if ALL of the plates separate (OK, call this "issue 1a": Do they? And are all of them not warped at all?), the oil bath and residual oil on the friction plates will transmit power through the assembly. "Bouncing" is not normal.
There have been several cases of people using the "wrong" oil here - it's not just viscosity, but what is the additive mix of the oil used. Some oils are touted as being ok for wet clutch use, others are definitely not.

2) Of course the amount of fluid in the master cylinder will have an effect - that's what transmits to the action down below. I know my bike is different from yours, but my experience has been that "just a little less" seems to work pretty well. That seems to be the only "adjustment" available.

Which may point another item to examine: Might there be a leak down at the slave cylinder? A bad hose? Or possibly an issue with a throwout bearing or the clutch's pushrod? The fiche shows the rod as actually being 3 separate pieces; I've seen a few HD's with similar rods that were worn and/or mushroomed on the ends.

Hopefully this can be solved while you're still under warranty; good thing that you've already formally informed the dealer so it's on record. Maybe they'd let you chat with a Master Service Tech instead of a "service manager" or a "service writer" - an actual rider who's actually savvy with a wrench.

Thanks for the ideas. I plan to remove a teaspoon of mineral oil from the clutch reservoir tomorrow when I am doing some maintenance on my other bike. As far as the other issues. The bike only has 13,000 miles on it and I would be surprised if the plates are warped. I have changed the oil myself and used BMW oil recommended by the BMW store (very expensive).

I read an article in my recent BMW magazine about not overfilling the oil when changing. It stated that it is best to add only 3.8L instead of the recommended 4L. Adding 3.8L at oil change puts the oil at mid level in the site glass. Mine sits at the top of the site glass currently.

There is no leak whatsoever at the clutch reservoir. I am also wondering if possibly the slipper clutch might be contributing to the issue. This is also the first bike I have had with a slipper clutch. Am I right in thinking that "Enduro Pro" driving mode will disable the slipper clutch so one will have engine braking on the trails? I will try the bike in "Enduro Pro" mode and see if the pulsing stops.

Thanks again for all the suggestions. I'll also take it to a Master Mechanic and pursue it further.

dclarkfs1 said:

I am also wondering if possibly the slipper clutch might be contributing to the issue. This is also the first bike I have had with a slipper clutch. Am I right in thinking that "Enduro Pro" driving mode will disable the slipper clutch so one will have engine braking on the trails? I will try the bike in "Enduro Pro" mode and see if the pulsing stops.

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Sorry I'm coming to this late, but I'd like to throw my $0.02 in: you indeed may be feeling the slipper clutch.

BTW, the slipping arrangement is entirely mechanical; it can't be "disabled." The slipper function is provided by a set of opposing wedge faces on the clutch basket and opposing plate. When the rear wheel tries to over-drive the engine, the wedges move relative to one another to axially "spread apart" the clutch plates slightly, allowing the clutch's driven and driving plates to slip relative to one another. Conversely, the ramps also operate in the opposite direction, so that the greater the torque being transferred from the engine to the tranny, the greater the clamping force applied to the clutch plates to prevent slip as the bike accelerates.

When you are at a stop and bring the clutch out to the friction zone, you are effectively slightly "loading" the wedges against one another; it is entirely possible that the 2-3 "bumps" you feel when you pull the clutch lever back is the release of the pressure applied to the ramps and consequent tiny relative motion as the ramps "relax" relative to one another.

I have not noticed this on my RTW, but I haven't been looking for it -- I'll experiment during tomorrow's office commute.

If you haven't noticed it, your clutch is not doing it. It is so noticeable as to be unmistakeable. I have yet to remove a bit of mineral oil from the reservoir or take it to a master mechanic at another dealer.

clutch tbl

I had trouble similar to yours for the last 39,000mi and complained to dealer 4 times. Finally met a salesperson with another dealer who test rode it and said this isn't right called his mech who looked through BMW computer list and found BMW has updated a part in clutch that addresses this problem. It is not a recall but a fix if customer complains and bike meets build dates. My bike was built dec 2012. It was out of warranty but BMW did a good faith and replaced it no charge.It now works like a clutch is suppose to work. 2013 R1200GSW

I finally discovered the problem with the clutch. A knowledgeable mechanic found that occasionally there are two O rings placed on the banjo bolt that goes into the master cylinder reservoir. He removed one of the O-rings and the issue cleared up. Also it is MUCH easier to find neutral now as there is no friction being applied to the clutch plates. The lower photo shows the second recessed area that some BMW workers apparently think an O ring should be place. The official repair manual clearly does not call for two O rings.

dclarkfs1 said:

I finally discovered the problem with the clutch. A knowledgeable mechanic found that occasionally there are two O rings placed on the banjo bolt that goes into the master cylinder reservoir. He removed one of the O-rings and the issue cleared up. Also it is MUCH easier to find neutral now as there is no friction being applied to the clutch plates. The lower photo shows the second recessed area that some BMW workers apparently think an O ring should be place. The official repair manual clearly does not call for two O rings.

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Interesting catch. I am going to look into that on other Wetheads.

Thanks,

Jim