Vibration While Letting Clutch Out

[RossKean]

I don't know whether this is a "problem" at this point or just an observation of a different behavior than I have seen in the past. Today, I noticed when letting the clutch out when taking off from a stop, there was a noticeable vibration until the clutch lever was a third of the way out. (Much more noticeable starting off slowly or inching along in traffic, feathering the clutch.) Normally, I get smooth engagement without vibration. I tried a roll-on in fifth gear at highway speed and RPMs increased in proportion to speed (no evident clutch slipping). The vibration while letting the clutch out is evident only when starting off from a stop in first gear. No vibration once the clutch lever is all the way out and nothing noticed when changing between higher gears.

This is not awful and doesn't make the bike un-rideable in any way (at least so far). I'm just concerned that it may be an indicator that something is wearing out.

2007 FJR
166,000 miles
Rotella dino oil (I usually use the synthetic version but have used the white jug a number of times without issue)
(oil change is due)
Happens with engine hot or cold
Clutch isn't "grabby" - I have never had to "soak" the plates
Never overheated the clutch (parade syndrome, or following Harleys

)
All clutch parts are original. - Is this abnormal or typical after this many miles? I don't tend to abuse it too much.

Anybody else have this happen?

Trying to decide whether I should consider replacing the fibre disks or just let it go until I see evidence of clutch slippage. I assume the metal disks are OK.

 

[flyfisher]

When's the last time you changed your clutch hydraulic fluid? ff

 

[Mr Bill]

Check that everything is tight on the rear pumpkin. Lost acorn nuts on the rear end causes a shudder at slow speed acceleration just like you describe.

 

[RossKean]

When's the last time you changed your clutch hydraulic fluid? ff

Usually every two years - I am due this year to do clutch and brake hydraulic fluid. I wouldn't expect degraded clutch fluid to cause these symptoms.

Check that everything is tight on the rear pumpkin. Lost acorn nuts on the rear end causes a shudder at slow speed acceleration just like you describe.

I will check but I get the vibration even if the bike isn't moving at all. i.e. holding the brake and letting the clutch off slightly.Edit: Just checked and acorn nuts are present and snug.

 

[Fred W]

I noticed some of that on my 1st Gen, but it was never too severe. I believe it was when I was running Rotella 15w40, which I did for a lot of my tenure. I later switched to Mobil 1 15w50 and I don't remember it happening much if at all. Might be worth a shot. Or, just pop the clutch cover off and take a peek at the clutch plates. It doesn't require much work to get in there. You don't even have to drain the oil.

 

[RossKean]

I noticed some of that on my 1st Gen, but it was never too severe. I believe it was when I was running Rotella 15w40, which I did for a lot of my tenure. I later switched to Mobil 1 15w50 and I don't remember it happening much if at all. Might be worth a shot. Or, just pop the clutch cover off and take a peek at the clutch plates. It doesn't require much work to get in there. You don't even have to drain the oil.

Since I am due for an oil change pretty soon, I may try that before anything else. I have a jug of the 15W40 dino Rotella on hand as well as some of the 5W40 synthetic Rotella. I might even switch to the Mobil 1 15w50 - Rotella used to be a dirt cheap synthetic oil option but I can usually find as good or better price for the Mobil 1 on sale.

What are the chances of the gasket surviving clutch cover removal? Wondering if I should have one on hand if I decide to examine the plates.

 

[Fred W]

I've done the job twice. Once on my 05, to do a clutch soak that it didn't need, and once on my '14 to put the slipper assist mod in. In both cases I had the gasket on hand but did not need it. Even if it does tear a little, the case is not under high oil pressure. A little smear of gasket sealer or silicone sealant would set things right. Just be sure to use O2 sensor safe sealant if you care about your lambda sensor.

 

[RossKean]

Thanks Fred. I've had the timing cover off at least three times and am still using the original gasket - maybe because I bought a spare "just in case". I do have some O2 sensor "approved" silicone although it probably wouldn't matter in a location that doesn't get terribly hot or see any of the combustion process.

Anyway, I'll try the oil first before I go further. I'm certainly not going to order friction disks until I'm sure that's what is wrong. I have encountered slipping clutches before but never this sort of vibration so I'm hoping the disks are OK. While my usual riding habits are reasonably clutch-friendly, it is getting a little long in the tooth...

 

[Viper Pilot]

If you intent to keep your FJR for awhile and you don't mind spending a little, I would recommend looking into installing the slipper clutch Fred mentioned. If you are going to be playing around the clutch assy. you might as well upgrade it to the latest slipper clutch design. I recommend it highly and the cost is nominal and the installation very simple.

 

[RossKean]

If you intent to keep your FJR for awhile...

What do you consider awhile?? I doubt that the investment would be worthwhile at this point (10 years and 166,000 miles). I did read Fred's postings on the slipper clutch with some interest but that is as far as it went. I'm guessing $400-$500 USD (minimum) by the time I'm done since I would be replacing at least the fibre disks at the same time. If the bike was a lightly used one with fewer than 40,000 miles on it (and at least an early Gen III) I would give it some very serious consideration. While I can hope my FJR will last another 100,000 miles, there aren't many that have gone that far.

 

[Brodie]

Ross

A clutch bleed won't take that much effort and will only cost you a couple of dollars for the container of Dot 4. It's really easy on the clutch housing gasket too. I know that with my Advanced Edition it's real easy to induce clutch shudder with letting some air into the line intentionally. A clutch bleed took it right out again. It will only take a little of your time, and as you said it is due for a flush anyway.

Brodie

 

[RossKean]

Ross
A clutch bleed won't take that much effort and will only cost you a couple of dollars for the container of Dot 4. It's really easy on the clutch housing gasket too. I know that with my Advanced Edition it's real easy to induce clutch shudder with letting some air into the line intentially. A clutch bleed took it right out again. It will only take a little of your time.

Brodie

Clutch (and brake) fluid exchange are due but I haven't gotten around to it yet this year. I think I will do that BEFORE changing the oil. Not because I am not doing both anyway but because I would like to know which (if either) was the cause. I don't think that "bad" (wet) DOT4 in the clutch would be an issue but I can see where a bubble might cause a problem.

 

[Fred W]

Cost of the slipper assist upgrade is right at $300 all in, which includes all new friction and steel plates, new springs and a new hub. But with your clutch having as much use on it as it does I'd want to have a close look at that clutch basket before committing that much cash into upgrading it.

PS - I don't really see how the hydraulics would be involved in the chattering. It really has to be some sort of irregularity in the friction parts that causes the vibration during slipping.

 

[RossKean]

PS - I don't really see how the hydraulics would be involved in the chattering. It really has to be some sort of irregularity in the friction parts that causes the vibration during slipping.

My initial thought as well but the fluid replacement needs doing anyway. That (and the engine oil) will be done before I tear into the clutch itself. If there are major issues with the clutch (basket, steels and friction disks), it might be worth considering getting a replacement eBay clutch or a whole motor given the mileage I have on it. I had forgotten that your clutch transformation cost was for everything including the steel plates and friction plates. (Didn't go back and re-read)

 

[Fred W]

Which means that I have a full set of clutch plates and hub with only about 10k miles on them that I might be talked out of. I don't ever see going back to the non slipper.

 

[mech 1 twa]

My Gen I did this from new. It never bothered me that much.

I replaced that engine with a 07 Gen II do to gear box issues. Gen II is smooth no issues with it.

I did have a stumble or misfire issue that turned out to be a bad TP sensor. Throttle position sensor. It would only stumble when throttle is first opened. Its a know problem mostly Gen I but a few others with newer bikes have had some problems also.

 

[RossKean]

Which means that I have a full set of clutch plates and hub with only about 10k miles on them that I might be talked out of. I don't ever see going back to the non slipper.

I'll keep that in mind and perhaps make you an offer you can't refuse (if I find I need to go the way of parts replacement). Probably won't find the time to do anything in the way of maintenance and diagnostics before next weekend.

 

[John d]

My first guess would be a worn out clutch bearing - Part 15 in the diagram.

 

[RossKean]

My first guess would be a worn out clutch bearing - Part 15 in the diagram.

Will do the oil and hydraulic fluid first. Next stop is to open the clutch to examine the guts. Any way to determine a bad bearing short of dismantling to that point? (I never encountered this before.) I appreciate the suggestion and it will definitely be on the radar. At least the part isn't stupid expensive.