Strange helicopter noise

[helicopterjim R.I.P.]

Curiously I ask 'how does the broken clutch plate make a whining noise'.

[callison]

Curiously I ask 'how does the broken clutch plate make a whining noise'.

48625[/snapback]

 

Hmm... maybe pictures will make more sense than words.

 

 

 

 

 

 

 

The clutch plate breaks at the center plate. The broken center piece can migrate off of the clutch hub and can spin about the engine shaft - the whirring sound. If this were all that it did, you could just keep riding for a while, but unfortunately, the broken piece can grind at the face of the case.

 

Incidentally, this is from a 97 California, but the clutch plates (latest version) are the same as those on the V11 Sports with dual plate clutches.

[helicopterjim R.I.P.]

Nasty!

[twhitaker]

I don't understand how a clutch plate, even a broken one, would make a noise after the engine is stopped, unless the noise is the shrapnel falling to the bottom of the housing.

[jrt]

OK, Robb, is the helicopter noise before or after you shut off the engine?

How does the clutch engagement feel?

 

When I lost a plate off my eldo, the engagement was often smooth, but occassionally very 'chattery' like the gears in the transmission were banging against one another (they were). It was worse when hot.

There should be additional vibration in running the motor as well, since it will be unbalanced now.

 

And if you have the correct tools, a clutch job is a long afternoon depending on how fast you work and how much beer you drink. I have an alignment tool I could loan you, but I only have the transmission input spline tool for the 2mm old (really old) style.

oh- nevermind- the bikes still under warantee...even better!!

Jason

[callison]

I don't understand how a clutch plate, even a broken one, would make a noise after the engine is stopped, unless the noise is the shrapnel falling to the bottom of the housing.

48644[/snapback]

 

Okay, you see the part in picture #2? It slides forward off of the splines in picture #1 and freewheels about the shaft, picking up rotational velocity with friction and then spinning to a stop after the engine has ceased rotation. Capiche? It sounds like a roulet wheel, yet the clutch can seem to be working quite normally. In reality, you now have a single plate clutch, well, there are two, but only one actually engages to the shaft to impart any energy. The outer portion of the clutch plate (picure #3), now that it's separated from the center "spider", remains captured in the clutch assembly and does not indicate any noticeable unbalance for this kind of failure. If the clutch plate surfaces come unbonded, then there will be lots of vibration and pieces at the bottom of the bell housing. For a while, Guzzi on riveted the plate material. That failed. So they bonded it. And that failed. Now MG both rivets and bonds them and the plate material stays put under nearly all normal circumstances. So, the center part breaks instead. The clutch in my California probably gave out because I took the bike into a fairly spirited ride with Mike Stewart and others at the Prescott Rally 4 years ago. Lots of strain from shifting near redline etc. Great fun but mechanically non-trivial when the parts fail. The California's/EV's etc are NO fun to pull the swingarm on. The V11 Sports and even the slightly less refined (but ever so much more svelte looking - but not weighing) Sport 1100i/Daytona RS bikes are very much superior from a chassis maintenance standpoint. Except for that foward zerk fitting on the driveshaft. PITA that one.

[twhitaker]

Oh! Makes perfect sense now.

[Skeeve]

I hope you are referring to the fact that for everytime they take off they have to land. Otherwise I'll have to contact the Transportation Safety Board and get a copy of the report that shows helicopter logging the second safest type of aviation after the airlines (and a very close second at that!).

48571[/snapback]

 

Maybe on a per flight basis, but no chance on per mile travelled. Unless the TSB is seriously doctoring stats. Of course, even on a per flight basis they're not including military flights, since I seem to hear of at least one fatal helo crash per year, usually with 6 or 7 soldiers/sailors/marines listed as casualties.

 

Helos can go into auto-rotate [autogyro] mode when the motor conks out, *if* they have enough altitude and a pilot who doesn't panic. But it's not a certainty, & if they don't, then a helicopter is just a large, oddly shaped rock following a trajectory that invariably points *down*... So in short, the only thing that keeps a helo in the air is man-years spent in design and esp. maintenance. That & Bernoulli!

[BrianG]

Maybe on a per flight basis, but no chance on per mile travelled. Unless the TSB is seriously doctoring stats. Of course, even on a per flight basis they're not including military flights, since I seem to hear of at least one fatal helo crash per year, usually with 6 or 7 soldiers/sailors/marines listed as casualties.

 

Helos can go into auto-rotate [autogyro] mode when the motor conks out, *if* they have enough altitude and a pilot who doesn't panic. But it's not a certainty, & if they don't, then a helicopter is just a large, oddly shaped rock following a trajectory that invariably points *down*... So in short, the only thing that keeps a helo in the air is man-years spent in design and esp. maintenance. That & Bernoulli!

48703[/snapback]

 

OK, so this from a guy on a "donor-cycle"??

[jrt]

Okay, you see the part in picture #2? It slides forward off of the splines in picture #1

48661[/snapback]

 

You must mean backwards, or toward the transmission. That's only if the aft plate is the one that busted. If it's the front one, it would be stuck on the transmission input spline between the flywheel and the aftward clutch plate. Not trying to be antagonistic- just trying to understand what's going on. Very interesting, and I think that is a plausible explanation.

 

huh- two completely independent conversations going on.

J

[callison]

You must mean backwards, or toward the transmission.  That's only if the aft plate is the one that busted.  If it's the front one, it would be stuck on the transmission input spline between the flywheel and the aftward clutch plate.  Not trying to be antagonistic- just trying to understand what's going on.  Very interesting, and I think that is a plausible explanation.

 

huh- two completely independent conversations going on.

J

48707[/snapback]

 

Some direction or the other. This was 3 years ago and I don't even want to think about the amount of trouble that particular clutch rebuild caused me. I got so PO'd I left the bike in pieces for 18 months.