Clutch noises on sporti

[bigpants]

Hi everyone. Well some unusual early spring sunshine and more importantly dryness means I've been able to get out on the sporti this week after a winter of tinkering. And everything seems fine except for the clutch which I promise I have not been near. So when I pull away it makes a dry graunching noise. Not a pleasant sound . It seems if I am careful , pull away slowly , with no revs it is ok. So far there is no clutch slip. Any ideas ?

[Beowulf]

Im just gonna throw this out there not knowing much. Throw out bearing maybe? Im sure others will be along shortly.

[guzziboy66]

Im just gonna throw this out there not knowing much. Throw out bearing maybe? Im sure others will be along shortly.

Agreed.  Sounds like the throw out bearing.

[bigpants]

Hmm , is there any secondary thing I could listen or feel for to confirm throw out bearing. I had a clutch replacement done about 2000miles ago if that helps.

[Beowulf]

Do you know if the throw out bearing was actually replaced when the clutch was?

[Old Jock]

I don't know as I've never had that sorta noise

Are we talking about the small thrust bearing that stops the actuating rod from spinning?

Personally I dislike the term "Throw out bearing" it doesn't throw out anything, as I understand it.

IF it is the "throwout bearing" then although a bit of work to get to it's not a gearbox off job.

Back wheel and swinging arm off to get into the back of the box (well it is on the Magni). The bearing can be accessed by moving the clutch actuating arm on the Gbx endcase out the way, then pulling the plunger with the O ring out, it may feel a bit reluctant, and the bearing and it's runners are inside.

You'll probably need long nose pliers or some form of forcepts (can be gotten off Amazon for not much money)

John

[tazio]

Universal joint good?

[n3303j]

Throw out bearing would be a continual noise when clutch lever held to the bar. It would go away when the lever was completely relaxed.
Check other options. Gears, bearings, universals, splines, couplings.

[Wayne Orwig]

The throw out bearing is at the rear of the transmission near the swingarm. Not hard to replace from the outside. Not likely to be the noise. If the bearing gets dirt in it and locks up, it will just spin the rod in the cup. It will damage things, but not make much noise.

Maybe it is just rust on the clutch splines from sitting. Or maybe a clutch plate failing.

Does the clutch still feel right?
Have you inspected the u-joints?
 

[malik]

I've always had trouble isolating noises. Are you sure it's the clutch? Not the gearbox? Nor the disc rotors?

[Moparnut72]

I had a similar issue with an Airhead BMW, the bearing on the transmission input shaft failed later in the summer. The noise occurred in the cold winter. BMW specified the wrong oil so the bearing wasn't getting proper lubrication in the cold weather. The bike was my only transportation at that time in Colorado.
kk

[Turin]

Any unusual vibrations ?

[John A]

If it had a ujoint carrier bearing, that’s what they sound like when they are on their way out. After a little noise when you first start out it quiets down but make no mistake, it’s going to fail.  I don’t think spine frames have one so I guess my point is that it might not be the clutch. It hopefully is just the clutch splines, they are not lubricated so if that is the case, it’ll stop making noise as you run it.

[leroy_can]

  I would tend to think the time spent unused is at fault. If the bike was washed before being stored or high humidity existed where it sat a little rust on clutch surfaces may need a good hard flogging and it may be fine. My car's rear drums had  horrible noises whenever it sat for a few days in the summer especially if it was damp out. One good hard stop would cure it until it sat again. The linings had lots of material but finally I replaced them and it's much improved. If I am correct a good hard ride should show a marked improvement but that might be hard advise to accept if you feel something is failing that you might make worse. I assume it was fine when put away last fall?

[Chuck in Indiana]

^^^^^ that is my first thought, too.

[bigpants]

A big thanks to everyone for their input , I'm sorry I wasnt able to get online to read the replies until just now ( 9.40pm in UK). I will go over the replies properly in the morning and try to answer everyone's questions. And I didnt realise the throw out bearing was that little one at the back. That has been replaced not that long ago. Sorry to be brief , long day at work and beer and bed beckon.

[Tom]

+1 on the rust. 

[bigpants]

Ok so I've just had a good read through the replies.
The clutch was replaced like I said about 2000miles ago. But at the time I had no money and the shop offered a good but secondhand clutch as part of the deal so there is always that.
The clutch action is sharp with precise control needed but it did work fine before winter. It still seems to work fine and is as sharp as before but now on release can make this loud , dry , powerful sound. There are no undue vibrations as far as I can tell.
There were several mentions of universal joint - excuse my ignorance here but are you talking about the uj's on the driveshaft ? I ask because I've had this and the rest of the back of the bike apart dozens of times in the last few months.
Im going to head out to do a few miles today and see if anything changes.

[Old Jock]

There were several mentions of universal joint - excuse my ignorance here but are you talking about the uj's on the driveshaft ? I ask because I've had this and the rest of the back of the bike apart dozens of times in the last few months.

Only UJ's I know of on the bike are the 2 on the driveshaft.

Have they been greased recently/at all? Depending on the date, but I believe most of them have grease nipples on them now to lubricate them.

It's not the easiest of tasks, as (well in my case) a special adaptor and hose onto the grease gun and even then they are still hard to get to. Something akin to this and a hose on the gun worked for me



I don't think this is the problem (as it would result in noise all the time) but just check the UJ's are aligned correctly as per the manual.

As I vaguely recall they should offset each other by 90 degrees and was there a spring in there to act as an shock absorber for the axial movement?

It's probably as many others have said just some corrosion, a good run out though should prove or disprove that theory.

[bigpants]

The driveshaft is one of the few areas where I have a fairly high degree of confidence as I didnt refit it. It and the drive box were redone by my local older bike specialist. He has lots of experience with cossacks , urals,  beemers and the like and also tractors , trucks or whatever you have. I will say that the driveshaft isnt totally straight , with the back off the ground if you spin the wheel you can see the shaft isnt true. But as far as I know it's always been like that . Anyone got a spare for sale ?

[bigpants]

Ok , quick update after a test ride. The noise is at the point of clutch release , it is a rather unpleasant mechanical protestation noise , loud enough to hear through earplugs. And when it happens the clutch grabs and the bike lurches forward. It appears to have got slightly worse.

[Wayne Orwig]

Probably a fractured clutch plate.
I've had that happen more times that I care for.

[bigpants]

Hmm. It would appear that the next thing is to start looking in there. Anything I should be particularly aware of or need in advance ?

[Old Jock]

About the only thing you'll need AFAIK, if you're not going into the box is either some sort of old spline and some know how to make a tool or an off the shelf special tool for decompressing the springs when you take it apart and then again for keeping the plates aligned when you put them (or new ones) back in.

Do all the usual checks, friction & intermediate plate thickness and spring heights etc: to make sure that when you put it all back you won't be having to in there again soon.

When you have the shaft out it might be a good time to grease up the UJs as they're a right old pain to do in situ.

Check the O rings and throwout bearing condition as well when the box is out, easy to do and doesn't require taking the box apart

That's all I can think of but sure more knowledgable heads will have some other ideas

[Chuck in Indiana]

Ok , quick update after a test ride. The noise is at the point of clutch release , it is a rather unpleasant mechanical protestation noise , loud enough to hear through earplugs. And when it happens the clutch grabs and the bike lurches forward. It appears to have got slightly worse.

Hope you like seafood. Looks like a crab is in your future. 
Edit: Oops, it's a Sporti. No sea food with that one.

[bigpants]

Blimey I feel completely out of my depth here. I am really not sure what I'm doing at all and I've only got limited resources here. I'm going to try to remove the engine and clutch leaving the gearbox there. I've only just put the bloody thing back in the frame.

[Old Jock]

Not 100% sure as my Sporti has a Magni frame so it's a little different, but not that much it's still the big box section spiney.

On more than one ocassion I supported the sump and then got a jack under the lower gbx mount to the frame. Removed the rear wheel, shaft, bevel box and swingarm (swinging arms in the case of the Magni as there are 2 on that bike)

No help whatsoever, only me (I don't have any mates) a screw and scisssors jack

Removed the gbx upper plate at the gbx and the lower pin to the frame as I remember. After some jack repositioning and leaving the engine supports in situ, although I do think I loosened them off, and a bit of jiggling with the frame I was able to drop the box and move it clear. That's the way I'd do it, I wouldn't try to remove the engine and leave the gearbox in place, the gearbox is much smaller and easier to remove/manhandle

It would be quite feasable to do with a couple of jacks or even a milk crate/blocks of wood and a scissors jack at a push.

I've never heard of anybody removing the engine to get to the clutch I think it would a lot more difficult, others will no doubt chime in with what they think

[bigpants]

Hmm, I should of read that post before I got the socket set and shandy out. But to be honest things have gone well. I chocked up the sump. Took off headers and injectors , unplugged a few wires. Front subframe off , starter off , undo bell housing nuts , give it all wiggle and its opened up. At this stage I've no idea what I'm looking for , I was hoping a broken piece would fall out the bottom . Gonna look at some pictures in the book just to check it all looks like it should .

[Old Jock]

Ah well I've learned something too BigPants

Yup that looksgood from what I see, but now you'll need to remove the ring gear to get at the friction plates and intermediate plate, which are behind the ring gear.

To stop the engine rotating when you're undoing the cap screw you'll need to either lock the engine from the alternator end or use the engine locking tool, that bolts onto the crankcase and locks the ring gear, or do what I did when I didn't have the locking tool and just made some small wooden wedges, jammed them between the ring gear and the studs and that worked well enough for me

Be careful this is where you need something to compress the plates, if you don't then there's a chance you'll damage the plates or the threads on the basket which the starter ring bolts onto to. Although I've just evenly undid all the bolts a bit at time in the past the starter ring will shoot off with a bang and there is a chance you could injure yourself (or worse damage the bike). There are I think 8, springs behind the plates so the plates and springs need to be compressed before disassembling.

Good luck

[Wayne Orwig]

Hmm, I should of read that post before I got the socket set and shandy out. But to be honest things have gone well. I chocked up the sump. Took off headers and injectors , unplugged a few wires. Front subframe off , starter off , undo bell housing nuts , give it all wiggle and its opened up. At this stage I've no idea what I'm looking for , I was hoping a broken piece would fall out the bottom . Gonna look at some pictures in the book just to check it all looks like it should .

From that picture, the hub splines appear to be deeply notched. Hard to image that is it, but that is also not a good thing.