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Diagnosing Slipping Clutch Problem


Jacob Ezzell

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After breaking out my v11 sport for the first time this spring and being thrilled that it all seemed to be great after its long winter's nap, I'm pretty sure I was feeling the clutch slipping. I'd be heading off from a stoplight and feel like the engine was racing just a little faster than I was actually accelerating. So while doing a steady 30ish mph, I gunned the engine in 3rd gear, and sure enough the tach revved high without much actual acceleration. Bugger.

 

It's a 2000 v11 sport with a little over 30K miles. I've only had it about 18 months, the PO's did the transmission recall work and had the flywheel "lightened and balanced." It's had at least 23000 miles on it since that work was done.

 

So where should I start poking around? I don't see any obvious leaks but I read in some of the other slipping clutch threads that it might not take much. How easy is it to bleed the clutch? I guess I'm asking what can I do without having to pull the rear wheel and subframe? I read about some people cleaning the clutch plates in place with brake cleaner, but couldn't find a good description or pics of how to do that.

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Can you feel enough play at the lever? How does the lever feel? Somehow I don't think that the problem has to do with the disks. I'd start searching at the lever and maybe loosen the adjuster screw there for a half or even one complete turn.

 

Hubert

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Bleed the lines THOROUGHLY. Even the slightest amount of air can cause problems. I thought I was having serious transmission problems myself until I tried the simple fixes first. Your lever should be very firm all the way, to the point of it being hard to pull.

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An easy thing to check is whether you have any small drops of oil leaking underneath at the back of the engine. If the seal has gone this could be contaminating the clutch- it has happened to me before.

Hi

 

I agree. Any issues with the hydraulic actuator will make the clutch difficult to disengage,because it will not overcome the clutch springs. Any slipping is nothing to do with the hydraulics. Look for oil leaks either from the engine crankshaft or the gearbox drive shaft. This will show as drops at the bottom of the bell housing as my learned colleague has indicated. If it's not that, plates are very worn, or springs are weak, probably the former. Either way you will have to split engine and gearbox to find out - about 2 hours work with the swinging arm out.

 

Cheers

 

Guzz

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I have a 20000 V11 and had to replace the clutch at 16,000 miles. The plates had seperated the friction material from the disk.

The rivits had failed. On mine it was almost like a two stage clutch, it would start to grip then slip, then grip again when pulling away from a stop. I think this rivit fail was common at one time and has been replaced by most already. Or could just be worn plates.

Either way looks like your are going in,took me a weekend, get the parts together, crabb the frame or pull the engine, I crabbed the frame.

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An easy thing to check is whether you have any small drops of oil leaking underneath at the back of the engine. If the seal has gone this could be contaminating the clutch- it has happened to me before.

Look for oil leaks either from the engine crankshaft or the gearbox drive shaft. This will show as drops at the bottom of the bell housing as my learned colleague has indicated. If it's not that, plates are very worn, or springs are weak, probably the former. Either way you will have to split engine and gearbox to find out - about 2 hours work with the swinging arm out.

 

Cheers

 

Guzz

 

Based on the suggestions to start looking for leaks, I started hunting, and may have found something. I apologize I'm sure my descriptions are off. On the left side of the bike, below the starter cover, and above where the oil pan split and all those bolts is some oil that looks like its very slowly leaking from between the engine shell and the transmission. it's a little forward of where the transmission lever goes into the transmission.

 

There's a significant amount of oil and crud on what I think is a window into the transmission, and some around the bolt that goes forward into the engine case.

 

High res pics are hosted at the following link: -->Picasa Album click here

 

IMG_1060.JPG

 

IMG_1062.JPG

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If the oil leak is between the engine and the transmission ie. rear main seal or trans input shaft seal that will cause a slipping clutch. If you look at the bottom of the engine where the trans and engine mate up you will see a little cutout on the line to allow a leak in the bell housing to escape if that is where the leak is its a seal.On the first picture that is the shaft the pawl spring and selector set on. I cleaned it up put sone tribond in, then a dime (it fits) more tribond on the dime and the leak is gone. This was suggested by another on this site and it works.

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If the oil leak is between the engine and the transmission ie. rear main seal or trans input shaft seal that will cause a slipping clutch. If you look at the bottom of the engine where the trans and engine mate up you will see a little cutout on the line to allow a leak in the bell housing to escape if that is where the leak is its a seal.

 

I can't find the cutout you speak of, but I stuck my camera way underneath to get a different angle and I think I see the seal you are saying may be spoiled. It does look like a seal is gone, but I don't see how the oil could get from here up to inside the clutch. :-/ Seems like it would be working against gravity.

 

IMG_1068_annot.jpg

 

On the first picture that is the shaft the pawl spring and selector set on. I cleaned it up put sone tribond in, then a dime (it fits) more tribond on the dime and the leak is gone. This was suggested by another on this site and it works.

 

Are you saying that the piece I called the "window" in my previous post is the "shaft the pawl spring and selector set on?" And that I can seal it up with a dime and some super strength epoxy?

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No seal there, its a cut out or wondow to allow rear engine main seal or trans input shaft seal leak to get out of the bell housing.

Clean the area well, take it for a ride and see if the seeping continues. No easy fix if the clutch is slipping it will need to be replaced. May as wall replace the seals when you are in there.

No not eppoxy use the case sealent and a dime on the leaking trans though eppoxy may work just not sure.

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If you have an oil leak thats getting into the bellhousing area it would only take a few drops to cause slipping. If you get a few more drops it may start to degrade the friction material. If its an oil leak thats causing the problem its only going to get worse. Maybe you could try an oil additive that helps to restore the seals. You might get lucky and it will actually work. Worst case scenario with the additive is it doesnt work and you're out a few bucks.

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...

I can't find the cutout you speak of, but I stuck my camera way underneath to get a different angle and I think I see the seal you are saying may be spoiled. It does look like a seal is gone, but I don't see how the oil could get from here up to inside the clutch. :-/ Seems like it would be working against gravity....

 

Attached photo shows slot in bottom of bellhousing (note that this photo shows transmission side & this is an old 5-speed box but V11 is very similar & as I recall has similar slot).

 

The oil will be coming from either the gearbox input shaft seal (shown in centre of my photo) or from the crankshaft seal opposite it on the engine side, if either is bad. Another possible culprit might be the crankcase breather that runs thru the bellhousing. All these are within the bellhousing & oil will drop down to the bottom of the casing & show there. The joint between motor & bellhousing is unsealed.

Check if it's gearbox or engine oil by smell.

In any event, if there's significant oil showing at the joint between the engine & the trans & your clutch is slipping, you will need to split the two to investigate.

 

Alternatively ...just read this on the WildGuzzi forum: "...if you've got a minor leak, you can try using thicker oil in the gearbox. 85W140 did the trick for me. My clutch started slipping at 19k when going over 85MPH, used white spirit to rinse the oil off the clutch plates, changed to gearbox oil to 85W140 and no more slippage. The bike now has 38k..." I've heard others report this, might be worth trying before pulling it apart? . When I put Redline Shockproof Heavy in the gearbox the minor leak I had from the gearbox sideplate stopped, a leak that I think you may also have (does leaked gearbox oil pool on the exhaust collector box?). But obviously if it's engine oil that's contaminated the clutch, this won't help!

 

KB :sun:

Tonti Gearbox Bellhousing.jpg

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Attached photo shows slot in bottom of bellhousing (note that this photo shows transmission side & this is an old 5-speed box but V11 is very similar & as I recall has similar slot).

 

The oil will be coming from either the gearbox input shaft seal (shown in centre of my photo) or from the crankshaft seal opposite it on the engine side, if either is bad. Another possible culprit might be the crankcase breather that runs thru the bellhousing. All these are within the bellhousing & oil will drop down to the bottom of the casing & show there. The joint between motor & bellhousing is unsealed.

Check if it's gearbox or engine oil by smell.

In any event, if there's significant oil showing at the joint between the engine & the trans & your clutch is slipping, you will need to split the two to investigate.

 

KB :sun:

 

I can't visualize this. Is this the inside of the clutch housing, facing towards the front or back wheel?

 

another dumb question, is it Engine->trans->clutch->wheel or engine->clutch->trans->wheel?

 

I did a ton of work on my old VFR, electrical, body, and carbs, but never had to crack into the engine itself, and I'm not thrilled at the prospect of tearing into my guzzi.

 

Can I get everything off with it up on one of the shop stands that holds it up by the bolt at the bottom of the porkchops, or will I need to pull those off too?

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I can't visualize this. Is this the inside of the clutch housing, facing towards the front or back wheel?

My photo is of the inside of the clutch housing looking towards the back wheel.

 

is it Engine->trans->clutch->wheel or engine->clutch->trans->wheel?

It's: engine->clutch->trans->wheel

 

Can I get everything off with it up on one of the shop stands that holds it up by the bolt at the bottom of the porkchops, or will I need to pull those off too?

There's various ways. To access clutch, I took motor out from front & left gearbox & back wheel in place. It's fairly straight forward & seemed to me easiest. I haven't done it another way. If you decide to do it, there's a "How to" thread & various others on this, which we can point you to.

 

Also Note the edit I added to my post above in between times!:

Alternatively ...just read this on the WildGuzzi forum: "...if you've got a minor leak, you can try using thicker oil in the gearbox. 85W140 did the trick for me. My clutch started slipping at 19k when going over 85MPH, used white spirit to rinse the oil off the clutch plates, changed to gearbox oil to 85W140 and no more slippage. The bike now has 38k..." I've heard others report this, might be worth trying before pulling it apart? . When I put Redline Shockproof Heavy in the gearbox the minor leak I had from the gearbox sideplate stopped, a leak that I think you may also have (does leaked gearbox oil pool on the exhaust collector box?). But obviously if it's engine oil that's contaminated the clutch, this won't help!

 

KB :sun:

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If you have an oil leak thats getting into the bellhousing area it would only take a few drops to cause slipping. If you get a few more drops it may start to degrade the friction material. If its an oil leak thats causing the problem its only going to get worse. Maybe you could try an oil additive that helps to restore the seals. You might get lucky and it will actually work. Worst case scenario with the additive is it doesnt work and you're out a few bucks.

 

I picked up a bottle of this stuff, is this what you are talking about? Anyone think it's a terrible idea for my guzzi? I once put some carb cleaner into my old vf500, and it ate up all the crud that was sealing the petcock together, made it leak like a sieve... I'm a little leery of additives now! :)

 

IMG_20120316_124607.jpg

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