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General Category => General Discussion => Topic started by: Testarossa on September 14, 2019, 03:56:23 PM

Title: Stuck clutch
Post by: Testarossa on September 14, 2019, 03:56:23 PM
Oy. I was doodling around town when the shift linkage came apart and I was stuck in third. I rode it home, only a mile, but to get up the hill I slipped the clutch pretty agressively.

When everything cooled down I popped the linkage back together (with plenty of loctite). The next day I went to start her up and the clutch is frozen -- that is, it won't disengage. I can wheel it around the barn in neutral, but as soon as I shift it into gear the wheel locks up and pulling the clutch lever doesn't disengage.

It's almost as if something fell out of the actuating mechanism, but I can see the lever pushing the clutch rod into the case. I'm about to pull the swingarm off for a closer look.

700 miles on a brand new Stein Dinse clutch with new clutch springs and inner body bearing, and the thing ran perfectly through the weekend at the Ouray NAR.

Any ideas?
Title: Re: Stuck clutch
Post by: Huzo on September 14, 2019, 05:08:32 PM
What would happen if you started the bike in neutral at idle and rolled it down a sight hill up to 10 mph, pulled in the cutch and popped it into gear.
Keeping the clutch lever in while the clutch is driving may crack the clutch free.
I am wondering if the heat you generated in the clutch has caused some contaminant to adhere the plates.
You won’t get anything like the force applied while the clutch is transmitting while driving, by attempting to crack it free by hand.
Title: Re: Stuck clutch
Post by: Muzz on September 14, 2019, 05:14:37 PM
The Honda GB400 I had would be left with a sticking clutch if left for a couple of weeks; it was of course a wet clutch and the oil would glue the plates together.

T free it i would nose the bike up to the side of the garage, put it in gear and pulse the start button. The shock would break it free.  In your case, with a dry clutch I would have no idea as to why it would stick.
Title: Re: Stuck clutch
Post by: Huzo on September 14, 2019, 05:24:52 PM
I’m guessing that when you got home you pulled the clutch in as you rolled to a stop and the clutch freed as normal.
You’ve then shut it off while idling in third.
This indicates nothing amiss so far.
Does the clutch action feel normal at the lever ?
Cable or hydraulic ?
Title: Re: Stuck clutch
Post by: Testarossa on September 14, 2019, 05:43:46 PM
Good ideas so far.

Huzo, it's a cable clutch and it feels absolutely normal. This is my plain-vanilla 850T.
Title: Re: Stuck clutch
Post by: oldbike54 on September 14, 2019, 05:52:36 PM
Good ideas so far.

Huzo, it's a cable clutch and it feels absolutely normal. This is my plain-vanilla 850T.

 You missed part of Huzo's question Seth . Did the clutch disengage normally when you stopped at your house ?

 Dusty
Title: Re: Stuck clutch
Post by: Testarossa on September 14, 2019, 07:41:02 PM
I believe the clutch worked normally when I arrived home. But sometimes I roll into the barn in neutral.
Title: Re: Stuck clutch
Post by: oldbike54 on September 14, 2019, 08:14:31 PM
I believe the clutch worked normally when I arrived home. But sometimes I roll into the barn in neutral.

 No snark intended Seth , but let's parse this out .

 The shift linkage was nonfunctional when you arrived home , correct ? So did you fix the linkage put the bike in neutral , then roll the bike into the barn , or did you leave it in 3rd gear and slip the clutch while rolling into the barn . The answer will provide a clue as to what is happening .

 Dusty
Title: Re: Stuck clutch
Post by: Testarossa on September 14, 2019, 08:26:56 PM
Righto, Dusty. Senior moments fly thick and fast these days.  Of course I had to have used the clutch entering the barn. So it was working when parked.
Title: Re: Stuck clutch
Post by: cliffrod on September 14, 2019, 08:50:09 PM
Maybe irrelevant, maybe not-

My V7 Sport, which I think has a comparable (if not identical) clutch arrangement to your 850T, had a sudden loss of all clutch function in heavy traffic in West Knoxville one day years ago..  NOT Cool. 

The clutch actuating rod had apparently somehow become jammed above of the seated position when I had recently had the bike apart trying to mitigate the badly worn square toothed input hub.  I had then adjusted my cable with the actuating rod not fully seated and it functioned that way for many miles. Then, when it finally dropped into proper position, I pulled in the lever and nothing happened.  I had been riding the bike a lot for a few weeks before this happened & it functioned normally until that moment.  Ultimately, I checked all I could think to check, found I could readjust things into proper operation enough to get home & then more adequately adjust everything and all was good.

If you've just had yours apart as mentioned, this might be something to check. 

Title: Re: Stuck clutch
Post by: Kiwi_Roy on September 14, 2019, 10:53:52 PM
Put the bike in second, pull the clutch then start it, if that doesn't work try a different gear.
Title: Re: Stuck clutch
Post by: oldbike54 on September 14, 2019, 11:22:10 PM
Put the bike in second, pull the clutch then start it, if that doesn't work try a different gear.

 Something tells me that isn't gonna help , dry clutch plates don't stick together like wet clutches do . Something is broken , or has come apart in the assembly that needs to be fixed . Plus the fact that it will be impossible to put in 2nd gear after it is running with a clutch that won't disengage  :grin:

 Dusty
Title: Re: Stuck clutch
Post by: wirespokes on September 15, 2019, 12:39:39 AM
Nothing new, really. My old Volvos did this a time or two, and maybe even one of my airheads. The clutch probably got hot, then drew in some condensation that stuck the discs.

The solution is to put the bike in gear like Roy suggests (but not while it's running!) - second (I've used first, but second is possibly better) - pull in the clutch lever - start the engine and hang on! With the clutch lever pulled in, the only thing preventing it disengaging is the stuck disc(s), so when it frees up, you're done. With the Volvo I had to give it the gas and let off a couple times before it broke loose. The extra torque both ways did it.
Title: Re: Stuck clutch
Post by: 80CX100 on September 15, 2019, 01:06:16 AM
Hhmmm,,, just thinking out loud, wonder if the major slipping of the clutch getting up the hill may have burnt/destroyed the thrust bearing on the push rod,,, or done damage to the end of the push rod;

As Dusty says, it sounds like something mechanical has broken/moved/shifted and you're not getting the full length of the push rod to push the plates apart, fwiw

good luck

Kelly

edit:     After thinking about it,,, could this be one of those cases where the extra thickness of your new clutch plates needs a longer push rod, or as I've read a ball bearing added to the end of the push rod assembly to give you extra length to push the thicker plates apart,,, maybe it just took the major slipping incident to bring it to light,, wag
Title: Re: Stuck clutch
Post by: Huzo on September 15, 2019, 01:32:06 AM
Nothing new, really. My old Volvos did this a time or two, and maybe even one of my airheads. The clutch probably got hot, then drew in some condensation that stuck the discs.

The solution is to put the bike in gear like Roy suggests (but not while it's running!) - second (I've used first, but second is possibly better) - pull in the clutch lever - start the engine and hang on! With the clutch lever pulled in, the only thing preventing it disengaging is the stuck disc(s), so when it frees up, you're done. With the Volvo I had to give it the gas and let off a couple times before it broke loose. The extra torque both ways did it.
You’ll maybe get away with pulling in the clutch and hitting the starter, but it’s a pretty cruel thing to do to the starter pinion, ring gear etc..
Really mate.
Roll down a hill.
Get to the speed that second gear would produce at 1000 rpm..(15 mph...?)
Pull in the clutch and engage second gear.
Even if you’ve not matched the speed exactly (and you won’t have), the rpm will be awful close and the engine will adopt the rpm required to engage the dogs without them seeing the light of day.
Now you have a sticking plate driving you along and you can put a bit of torque through it to see if it’s just stiction.
But you are not crashing two mechanical parts together at non sympathetic speeds relative to each other and the drive train is not being subjected to forces that it wasn’t designed to cope with.
Honestly mate...?
Just do it.
Title: Re: Stuck clutch
Post by: n3303j on September 15, 2019, 01:59:07 AM
Possibly generated enough heat to warp the intermediate plate so the stack height is now beyond your current clutch adjustment?

Just installed two SD clutches this summer. Both worked well but both required a bit of adjustment beyond the range required for standard thickness plates. The T3 got an extra washer added to the throw out bearing and a touch of adjustment on the screw that pushes it. The EV got full IN adjustment of the screw on the transmission side release arm.
Title: Re: Stuck clutch
Post by: Chuck in Indiana on September 15, 2019, 06:23:15 AM
Quote
The clutch probably got hot, then drew in some condensation that stuck the discs.
That was my first thought, too.
Title: Re: Stuck clutch
Post by: oldbike54 on September 15, 2019, 06:37:01 AM
That was my first thought, too.

 Maybe , but Seth is reporting that the clutch lever feels normal and he can see the pushrod working .

 Dusty
Title: Re: Stuck clutch
Post by: wirespokes on September 15, 2019, 09:10:38 AM
Of course the clutch lever will feel normal. The clutch spring and throw-out arm and all that is working fine. It's that the clutch doesn't float free when it's unclamped.

That's all.

And starting in first? If you point her down a slight down slope I don't think the starter motor will even notice it's in gear. Have you ever accidentally hit the starter without pulling in the clutch (and no safety cut out?).

Get the engine warmed up in neutral first, that way it'll start right up when you start it up in first. That would be the easiest on the starter, but frankly, when I've done this, the starter motor gave no indication it was a strain on it.

I always use the clutch to shift, unlike some of you. There have been times I've coasted and wanted to put it back in gear, even with the lever in, and haven't had good luck with that. Rather than rounding shifting dogs I've been careful and either not coasted in neutral, or made sure I was stopped before putting it back in gear. And that was even with the clutch pulled in. Maybe it was different with the airhead transmissions, or the way I was doing it, but I'm pretty careful of the transmission. Starters? They're pretty damn rugged, cheap and easy to repair. But transmissions aren't cheap, or easy - I've worked on them too.
Title: Re: Stuck clutch
Post by: Kiwi_Roy on September 15, 2019, 09:29:04 AM
You’ll maybe get away with pulling in the clutch and hitting the starter, but it’s a pretty cruel thing to do to the starter pinion, ring gear etc..
Really mate.
 

 I don't see it, press the starter button and the solenoid slides the gear into mesh, only once in mesh does the main contact closes and the battery puts the power to the motor.
The starter has a huge mechanical advantage over the ring gear, I'm sure you have ridden a bike with a broken clutch cable at some time in your checkered past lol.
Title: Re: Stuck clutch
Post by: John A on September 15, 2019, 11:00:51 AM
I had one that after replacing the clutch , unbeknowst to me, the rod was not in the center of the puck. When it went in to its hole, by its own accord, it had so much freeplay it would not release. Maybe its that but I dont know how you could tell.
Title: Re: Stuck clutch
Post by: Testarossa on September 15, 2019, 11:39:04 AM
Fixed.

Thanks for all the feedback. After considering all the advice, I put the bike on the centerstand so the rear wheel was clear. Put it in fifth gear. Held in the clutch, started the engine, watched the rear wheel spin up, then stood on the rear brake.

Voila. The wheel stopped spinning and the engine pottered along. Clutch now seems to work normally.

Whatever was stuck is un.

And BTW -- There's so little clearance around the clutch cable adjuster at the bottom end, it's often tough to get a 10mm and 12mm wrench in there. So I ground a lot of material off a couple of wrenches so they'll fit easily.
Title: Re: Stuck clutch
Post by: Chuck in Indiana on September 15, 2019, 11:44:38 AM
 :smiley:
Title: Re: Stuck clutch
Post by: wirespokes on September 15, 2019, 02:22:11 PM
Hey! Good idea (running it on the center stand)!

When I got the 85 LM from Long Island last year, it was last tagged in 91. I suspect it saw Sandy, but not horribly, and was cared for afterwards. Fluids all look good, minor corrosion here and there. Even the fork tubes weren't rusty. Once I got her running after replacing the starter (all rust inside) the clutch wouldn't disengage. Rode it up the driveway and back with the lever pulled in. No change. Pulled the trans to find the clutch rusted to the pressure plates.

Most times you win, then other times it's not just a minor situation. You know, I think I tried running it on the center stand first just like you did. When that didn't work, riding it up the driveway was the next gradient. And I believe I did that twice before deciding something more drastic was called for.
Title: Re: Stuck clutch
Post by: Testarossa on September 15, 2019, 02:43:57 PM
The first issue I had after I thought I'd completed the Triumph rebuild was, of course, a stuck (original) clutch. No amount of external fooling around could fix it so I learned how to replace a Triumph clutch (so much easier than a Guzzi!).

It occurs to me now that the extra thickness of the S-D plates may make this clutch, however smooth and efficient it is, less tolerant of overheating. At least we know now that stuckness due to plate expansion is easy to fix, once everything cools down.
Title: Re: Stuck clutch
Post by: Muzz on September 15, 2019, 03:26:45 PM
 :thumb: :thumb: :thumb: Good result Seth.
Title: Re: Stuck clutch
Post by: Aaron D. on September 15, 2019, 05:24:47 PM
Glad it's fixed-I don't understand the comments that dry clutches don't stick. I've seen it on Guzzis many times.
Title: Re: Stuck clutch
Post by: oldbike54 on September 15, 2019, 05:31:23 PM
Glad it's fixed-I don't understand the comments that dry clutches don't stick. I've seen it on Guzzis many times.

 In over 50 years of motorcycle riding I have never witnessed a dry clutch sticking . Dunno .

 Dusty
Title: Re: Stuck clutch
Post by: bmc5733946 on September 15, 2019, 06:29:11 PM
Over the years I worked at GT MOTORS we had several Guzzis come out of the crate with clutches stuck. Up against a wall and pop the starter in gear solved several, riding till hot (although not for the faint hearted) solved some, some actually needed disassembly and rust clean up.

Brian
Title: Re: Stuck clutch
Post by: Howard R on September 15, 2019, 06:45:31 PM
In Guzziology Dave describes escalating levels of drasticness to free clutches that came out of the crate stuck, ending with something similar to that described above: warm engine in neutral, low-traffic road with some room to maneuver, start bike in 2nd gear, pull in the clutch lever & give 'er the beans.  Might take a time or two of gassing & letting off to pop loose a clutch that had rusted/stuck on a slow boat from Italy.
Title: Re: Stuck clutch
Post by: Chuck in Indiana on September 15, 2019, 07:23:36 PM
In over 50 years of motorcycle riding I have never witnessed a dry clutch sticking . Dunno .

 Dusty

You need to come up to big temp swings of the frozen north, Dusty.. I have.
Title: Re: Stuck clutch
Post by: pehayes on September 15, 2019, 07:45:37 PM
Hey! Good idea (running it on the center stand)!

NOT!  I'm glad the clutch is now fixed.  In the variety of suggestions about how to resolve it, running on the center-stand might be the most abusive.  The engine rotation technology and angles of the drive shaft can create a lot of stress on the joint.  Not ever a good idea to run in gear on the centerstand.  I would have supported up against a wall and bump the starter.

Patrick Hayes
Fremont CA
Title: Re: Stuck clutch
Post by: Testarossa on September 16, 2019, 11:32:34 AM
Quote
NOT!  I'm glad the clutch is now fixed.  In the variety of suggestions about how to resolve it, running on the center-stand might be the most abusive.  The engine rotation technology and angles of the drive shaft can create a lot of stress on the joint.  Not ever a good idea to run in gear on the centerstand.  I would have supported up against a wall and bump the starter.

I thought about that, so I did some measurement with a level and protractor. On the T, with its original Koni shocks, the difference in shock length between laden and wheel-off-the ground is only about .5 inch (12.25 with my 150lb aboard vs 12.75 unladen). That translates to about 5 degrees difference in swingarm angle. I'm guessing 5 degrees doesn't hurt much under no engine load and idle rpm for about 60 seconds.

YMMV
Title: Re: Stuck clutch
Post by: pehayes on September 16, 2019, 12:42:55 PM
It is not so much about the angle of the shaft, but of the inertia of all of the moving parts between the crankshaft and rear wheel.

The Guzzi engine does not rotate in a smooth and even rotational speed throughout its cycle.  Due to the "V" design, resistance to compression, and thrust force from combustion there is no such thing as a steady rotational speed or 'constant' rpm.  The flywheel is alternately accelerating and decelerating for angular portions of each cycle.  High RPM with loads going down the road this is not detectable and has no adverse effect on performance or abuse to components.  However, at lower rpms like idle and with the rear wheel unloaded off the ground and with the inherent slop clearances in each gear cog mesh and spline mesh there can now be some very abusive forces delivered up and down the drive train.  The poor little needle bearings of the U-joint take the brunt of these unequalized forces.  It just isn't a good idea for mechanical reasons to run the bike in gear up on the centerstand.

Patrick Hayes
Fremont CA
Title: Re: Stuck clutch
Post by: Chuck in Indiana on September 16, 2019, 01:53:29 PM
I totally agree with Patrick.  :grin: I did it once with the Centauro looking for a noise, and thought, "Horry Carp!" That wasn't a good thing.
Title: Re: Stuck clutch
Post by: Testarossa on September 16, 2019, 02:17:44 PM
Understood!  Won't do it again.
Title: Re: Stuck clutch
Post by: Huzo on September 16, 2019, 05:32:16 PM
Understood!  Won't do it again.
One of the first posts I ever read here was from Pete Roper on that very topic.