Wildguzzi.com
General Category => General Discussion => Topic started by: lazlokovacs on January 26, 2022, 07:25:44 PM
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Hi
Can the gurus out there let me know if any of my understanding of the guzzi clutch is faulty?
I'm starting from the very basics so bear with me.
1 - as you squeeze lever, pressure plate gets pushed against flywheel, this leaves friction plates free for shifting, clutch is ENGAGED
2 - as you release lever, pressure plate springs back against friction plates and drive is transmitted to gearbox, clutch is DISENGAGED
3 - as friction plates wear, springs "spring back" further and the throw out bearing protrudes and you LOSE freeplay at the lever. (all else being equal)
4 - as pushrod or throw out bearing wear, thrust bearing recesses and you GAIN freeplay at the lever. (all else being equal)
5 - if engagement changes when hot - (increasing freeplay) then intermediate plate may be warped.
Correct me on anything I have wrong please!!!
My friend's new bike has a clutch that lurches into engagement incredibly quickly. His cable is bent and nasty, and the clutch was last adjusted by the PO who was quite possibly deranged and thought nothing of riding long distances with missing frame bolts!!! ...so I advised him to fit a new cable and set it up properly and then see where he's at. Will report back with results when we get them.
Just wanted to check my knowledge was good before I advise him any further....
Thanks guys. :thumb:
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I agree on 1-4. 1-3 is how a clutch will work as the friction plates wear out on a Guzzi. 4 would be as if there was an issue with the throw out bearing, clutch rod, or the cup in the pressure plate. 5 not sure??
Put a new cable on it if it is suspect. Not too much money to try that first.
At one time MANY years ago. One or both of my Loops adjustment would change after a long freeway run. I think it made the clutch engage quicker from the grip. Cool down and back to what it was before the freeway run. Never did figure out why (or can't remember??). Now......neither seem to do this (???).
Tom
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Careful. With a clutch, the terms ENGAGED and DISENGAGED are often confused and inverter by 180 degrees. Kind of like FLAMMABLE and INFLAMMABLE.
Most of what you wrote is very correct.
#2 - I would say that the pressure plate is pushed aft by the springs and thus squeezes the friction plates against each other and against the internal face of the ring gear cover plate.
The relative amount of wear to the friction plates and wear to the throwout bearing components are NOT equal. In real life, the friction material should wear more over time. Thus, the protruding is more normal and the recessing is cause for panic.
Usually the friction plate wear happens in a linear sense. Except for the first 1000km on new parts, the friction wear rate is usually constant over the life of the components.
The throwout bearing wear is very different. There is nothing and then suddenly there is a lot. The race washers of the bearing have a very hard surface and experience almost no wear for the life of the bearing. Once that hardened layer is penetrated, the wear rate of the softer underlying metal becomes dramatic.
The T3 is a very old bike. It either has high mileage or it sat for a long time. Neither condition is good for clutch components.
In my opinion, the very rapid and abrupt engagement is almost always associated with notching of the transmission input drive spline or notching of the interior splines on the flywheel itself. Neither can reliably be corrected without just installing new parts. All of these splines gather 'dust' from steel rusting and from friction decomposition. This forms an abrasive paste that digs into the metal of the components. It is possible to partially fill the clutch chamber with mineral spirits. The clutch becomes much more normal and smooth, but all the bad juju returns within 1000 km.
Sorry.
Patrick Hayes
Fremont CA
See some nasty notches on this transmission input spline.
(https://i.ibb.co/7VFPNg3/MVC-353X.jpg) (https://ibb.co/7VFPNg3)
upload (https://imgbb.com/)
The rust paste and notches inside the flywheel here:
(http://farm9.staticflickr.com/8386/8538727590_bea3d045dd.jpg)
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1 - 4 = OK
5 - if engagement changes when hot - (increasing freeplay) then intermediate plate may be warped. = Wrong.
When the temperature increases - the pusch rod will increase in lenght - so that the freeplay will be smaller.
Correct freeplay: Cable versus handle = should be about 2-3mm. Correct this every year.
Rolf
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Patrick's on the money i think. My T 3 did exactly as you described and the cause was a notched flywheel and input hub. An expensive repair but when you look at the amount of miles covered it becomes much less shocking.
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As for the reversal of engagement terms, my factory Norton Commando service manual explains that the clutch is a device used to interrupt power to the transmission for ease of shifting, It is engaged to remove the connection and disengaged to allow direct power to the rear wheel. Kind of makes sense. Most folks today equate the lever position to the clutch operation.
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I had Sureflex plates on the G5 cause exactly that problem. Had to install new flywheel, clutch plates and intermediate plate, and transmission input gear. It all happened in less than 20,000 miles. :shocked:
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Another term is intermediate plate, that disc that is between the friction material. On a funny car with a multiple disc clutch we call those floaters because they are loose when not clamped.
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Careful. With a clutch, the terms ENGAGED and DISENGAGED are often confused and inverter by 180 degrees.
Yes. The term "engaged" means coupled, that is the clutch lever is out and the engine crankshaft is coupled to the input shaft of the transmission. You disengage the clutch by pulling the lever.
(https://i.imgur.com/wY2z1l8.jpg)
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Yes. The term "engaged" means coupled, that is the clutch lever is out and the engine crankshaft is coupled to the input shaft of the transmission. You disengage the clutch by pulling the lever.
Finally Someone said it right. It was driving me nuts not seeing it explained properly.
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Yes. The term "engaged" means coupled, that is the clutch lever is out and the engine crankshaft is coupled to the input shaft of the transmission. You disengage the clutch by pulling the lever.
Finally Someone said it right. It was driving me nuts not seeing it explained properly.
Agreed. If you think about it in "mechanical" terms such as "engage the drive" on a piece of machinery or a "drive" mechanism then translate it to a clutch. When you engage the "drive" it's connected and disengaged it's free.
Ciao
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In reference to a previous remark concerning a hardened steel push rod growing enough to cause a marked difference in freeplay , kinda
misses the fact that the aluminum transmission case expands (grows) considerably more and that would add to clutch freeplay as the arm that pushes on
that rod is growing away from the clutch . Both my tonti framed bikes have this growing clutch lever clearance when hot and a return to normal
when cooled . Peter
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Agreed. If you think about it in "mechanical" terms such as "engage the drive" on a piece of machinery or a "drive" mechanism then translate it to a clutch. When you engage the "drive" it's connected and disengaged it's free.
Ciao
Correct as applied in todays mechanical jargon. It was described the other way back in the dark ages of pre and post WW2. Ultimately, the terminology has been sorted and we engage the clutch with a release of the lever.
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thanks guys, great replies
will let you know how my buddy's T3 turns out.
(Strange thing, all my friends have always ragged on me for riding guzzis and in the last couple of years they've all started buying them!!)
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thanks guys, great replies
will let you know how my buddy's T3 turns out.
(Strange thing, all my friends have always ragged on me for riding guzzis and in the last couple of years they've all started buying them!!)
:thumb: LOL!
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thanks guys, great replies
will let you know how my buddy's T3 turns out.
(Strange thing, all my friends have always ragged on me for riding guzzis and in the last couple of years they've all started buying them!!)
It *does* take a certain amount of "mechanical sympathy" and maturity.. :smiley: