Clutch issues, I think

[blade]

I have an 05 Connie with about 20K miles.  I haven't been doing a lot of riding the last couple years so she has sat more than she should.   I had her out a few times last year and she ran with no problems, up until I did an oil change. I accidentally put in a semi-synth that had friction modifiers. After the change I ran the bike up and down the street a couple times and noticed the clutch slipping. That's when I realized my mistake. I immediately dumped the oil and pulled the filter and put in my regular Rotella. 
The clutch still slipped. I left it sit for a few days to allow the new oil to soak in and tried to run her again.  Initially clutch released just fine after I first fired her up, but after she warmed up the clutch was slipping again. I once again dumped the oil and filter replacing it with Rotella fleet oil like I have for years. I let the bike sit a few days and tried again. Same scenario, clutch slips after the bike warms up.
I left it with plans to check it out over the winter, unfortunately work inserted itself into much of my free time, so I couldn't see what the problem was.

Fast forward to today, I pulled the bike out of her spot with plans to take he on a quick run to see what is going on.  I had it running to get it out of the garage and the clutch grabbed and released with no problem. I shut her down went back in the house to grab my gear. Out a couple minutes later and hopped on ready to go for a ride and the bike is going no where. I have it in first and the clutch released and nothing is happening. I rev it a couple times but nothing is happening, I am not getting any smell of burning clutch, no pulsing, just nothing. It's like the bike was in neutral.  I got it shifted into 2nd and 3rd and still no movement.

Up to this point she has had 3 oil changes since I realized the issue with the semi-synth, so there should be enough oil through the system to flush that out. I have checked the master clutch cylinder and it is full of fluid.   

I suspect that it has to be clutch related but I have no idea where to start.  Asking for some ideas as to what I could be dealing with here.

[Cholla]

have you checked to see if the rear tire will turn with the bike on c-stand and in gear?
Engine off, of course.

[turbojoe78]

When was the last time you changed the fluid for the clutch?

If it's been a long time your return hole, the very small one at the bottom of the Master Cylinder could be clogged.

When the engine is cold the clutch will work fine, but when it heats up, the fluid in the slave cylinder will heat up and expand and with no where to go because the return hole is clogged it will make the clutch release by itself.

Start with flushing out all the old fluid and make sure the return hole is not blocked, there are two holes in the bottom of the master, the smaller hole is the return.  Use a single strand of thin wire to carefully clean the hole.

[blade]

I can turn the rear wheel in 1st with the motor off, not as easily as in neutral, there is definite resistance, but not like I was actually fighting the motor.


I had flushed the clutch a couple years ago, but that was before this developed. I will see about clearing out the old clutch fluid.

[MAN OF BLUES]

you might just want to pull the rear wheel, and examkne the wheel hub, to insure that just by coincidence, the internal splines have not sheared off.... I've seen this many times, and there is no rhyme or reason in when it occurrs, but it happens.. and when it does.. everyone points to clutch... look closely.

[T Cro ®]

I can turn the rear wheel in 1st with the motor off, not as easily as in neutral, there is definite resistance, but not like I was actually fighting the motor.


I had flushed the clutch a couple years ago, but that was before this developed. I will see about clearing out the old clutch fluid.

I'd take advise from MOB on the rear spline but if you think that it may be the clutch slave causing your slip then simply remove it from the engine; it's just 3 bolts and a push-rod.

[blade]

Had a little time tonight and started with the basics by pulling the clutch master cover. Well things have changed since I last had that cover off. The fluid looked like strong black coffee. I put the mityvac on the bleeder and initially could get nothing to move out of the master but after a couple more pumps it pulled the dirty crap through.
I drained the cup and started bleeding again, still getting some nasty looking fluid coming out the bleeder. I started siphoning off some of the crud in the master and I am seeing small chunks off material in the bottom of the cup when I drain off the nasty fluid. I also am seeing some cloudiness that I am attributing to moisture.  Hopefully I can finish the flush in the morning before work takes over.

I am still going to check out the splines like MOB suggested, I'd be stupid not to listen to a good suggestion.  Plus I have a Meanstreak rim just waiting to be machined and an issue with the stock rim might just push that project to the forefront.

probably wouldn't hurt to pull the slave as well, just to make sure it's not full of crap as well

[Jim __]

If it's the splines on the rear wheel, it's a simple replacement, although a little expensive.  Just be certain to clean and grease the splines on the wheel and mating splines in the diff.  A little Honda Moly 60 grease painted onto the splines goes a long way and will not sling off.

[Cholla]

And while you have the wheel off go ahead and remove the bevel drive init andgrease the driveshaft/pinion splines and coupler.
And one other thing.....

[Riverszzr]

 I would expect the spline in either the drive hub or the driveshaft to make considerable noise if they are "sliding" past each other

But with as much slipping of the clutch as you have had- I would expect by now to see hot spots on the clutch steels and the frictions will be well burnished and need replacement

But that kind of "yuk" in your master... well I have not seen it cause clutch slipping- usually I have seen that cause more issues with trying to get the clutch to disengage. I have seen dozens of bikes come through with fluid that has a jello consistency of all sorts of colors and they didn't make the clutch slip

And with fluid that neglected, look at the bushing and the pivot bolt too--clean and lube them.

[MAN OF BLUES]

I would expect the spline in either the drive hub or the driveshaft to make considerable noise if they are "sliding" past each other

But with as much slipping of the clutch as you have had- I would expect by now to see hot spots on the clutch steels and the frictions will be well burnished and need replacement

But that kind of "yuk" in your master... well I have not seen it cause clutch slipping- usually I have seen that cause more issues with trying to get the clutch to disengage. I have seen dozens of bikes come through with fluid that has a jello consistency of all sorts of colors and they didn't make the clutch slip

And with fluid that neglected, look at the bushing and the pivot bolt too--clean and lube them.

we have seen almost a dozen bad rear wheel hubs in the last 5 years, and none of them made a sound,  and were only discovered by careful analysis.
so, it doesn't have to be audible to diagnose... last one was not many months ago.

as for the master cylinder, the small holes in the reservoir can block easily, and o/p noted gack in there also... if the return is blocked, the heat of the engine will pressurize the lines, causing partial disengagement, and slippage also...

I say this from a few years experience  this bike, diagnosing issues.  mostly from afar.

[blade]

Ok bike is moving again. Turned out that the return hole was blocked completely.  The master is cleaned out, fresh fluid added and bled.   I didn't pull the slave, but I did check and grease the splines.

Thanks for the help

[MAN OF BLUES]

Ok bike is moving again. Turned out that the return hole was blocked completely.  The master is cleaned out, fresh fluid added and bled.   I didn't pull the slave, but I did check and grease the splines.

Thanks for the help

good deal man, I only thru that hub issue out there as it has surfaced a few times, and people have chased the clutch without resolve..
 as I mentioned those ports in the m/c are prone to blockage, glad you followed the advic, and even happier it all worked out for you...
ride safe