850-T3 Clutch

[n3303j]

So there's 130,000 miles on my T3. The first flywheel developed notches that made the clutch drag when released. That made it difficult to get out of gear when stopped. So I replaced the flywheel with a lightly used one at 80K miles and all was fine for awhile.

Well I'm back to the same problem again beginning at 50K miles of use. So I assume the used flywheel has developed signifigant notches to interfere with clutch operation.

Figuring I might buy a fresh new flywheel, ship it out to a heat treat shop and have it case hardened. Should be able to get it to 62RC Rockwell about 0.005" Deep. This should stop the flywheel from developing notches.

Any reasons I should not consider this option.

Meanwhile my V11EV has 100,000 miles and clutch works fine. I had it apart at 85K miles and there was no notches in the flywheel or the transmission input spline. I thought these two machines shared essentially the same clutch? Why the different failure mode?

[faffi]

Perhaps the V11 runs smoother under load, or you ride it at higher rpm? I remember the BMW (sorry, turboguzzi) oilheads began stripping clutches when they went to a 6-speed transmission, with the 6th being an overdrive. That apparently caused owners to lug the engine too much, ripping out the splines.

[pehayes]

The notches appear both in the internal spline grooves of the flywheel body and also the external spline grooves of the transmission input hub.  Usually the transmission input wears quicker and more seriously. I have heard of various hardening techniques over the years but never a report of long term success.  Just buy new parts.

Patrick Hayes
Fremont CA

[n3303j]

The notches appear both in the internal spline grooves of the flywheel body and also the external spline grooves of the transmission input hub.  Usually the transmission input wears quicker and more seriously. I have heard of various hardening techniques over the years but never a report of long term success.  Just buy new parts.

Patrick Hayes
Fremont CA

Don't want to have to replace a flywheel every 60K miles. I have better luck with the transmission input spline. Things usually show occasional signs of hanging after 30K miles.

I don't lug the engine. It runs smooth & happy between 4K and 5K RPM all day long. Keeps the battery happy too as the alternator is delivering 14.4 through the solid state regulator.

Someone also mentioned adding radial slots with stress relief holes to the intermediate disk to keep it from heat distortion (like done on circular saw blades.

[moto]

I remember Pete Roper warned that a too-slow idle speed would tend to worsen these notches because the flywheel would have more time to slow up and down between the engine pulses and thus deliver bigger blows to the parts. Is your T3's idle too slow?

[n3303j]

I remember Pete Roper warned that a too-slow idle speed would tend to worsen these notches because the flywheel would have more time to slow up and down between the engine pulses and thus deliver bigger blows to the parts. Is your T3's idle too slow?

Idle around 1,250 to 1,300. It stops the clatter of the transmission in neutral and keeps the battery up. Makes everything smoother.

I tend to wonder if the transmission input shaft shares an identical centerline with the crankshaft. If they are not concentric the intermediate plate and pressure plate will constantly "walk" around the inner splines of the flywheel when the clutch is disengaged. This would accelerate wear.

It's odd that this bike keeps eating flywheels wheras both the V11EV and the Ural (Both dual plate dry clutches) are not experiencing these issues.

[guzzisteve]

I remember riders saying the trans is mounted off center. Maybe it's bad parts.

[John A]

What Steve said is a problem with some. The fix is to make a fixture that centers the transmission in relation to the engine, pull the alignment dowels and align it on center. Some make offset dowels, some get by with just bolting it in the correct position. There is probably instructions on This Old Tractor. If you’ve got one that uses up clutches I would suspect its out of alignment and check it. https://www.thisoldtractor.com/
It’s for loops but it’s the same https://www.thisoldtractor.com/moto_guzzi_loopframe_alignment.html

[MattP]

harden both flywheel and imput  flywheel can can only ware when clutch is pulled in raise iddle , how ever the imput is orbiting any time you are moving. hardening can not do anything but prolong the life of said parts  i was thinking of melinizing imput  hub.  low idle  clicks rite in 1st no clunk i like that. you can increas  tell you shift i think with the twist grip . bike may go faster also your walet  will be lighter

[MattP]

So don,t sit at stop lights in gear with clutch in. Flyweel splines can not posibly were when clutch is out. The imput however will

[n3303j]

Had to think about that one for a bit. The clutch pushes the bike through the friction material. The friction material is clamped against the cover plate and the intermediate plate by the pressure plate. The cover plate is screwed to the flywheel and transmits torque through those cover screws. The friction plate and pressure plate are both floating inside the flywheel and transfer torque through the teeth on the plates mating with the internal spline in the flywheel. If the alignment between the crankshaft and transmission input shaft isn't perfect there will be some radial movement in the clutch pack. This will promote wear. Probably more toward the plate nearest the engine.

Looks like I have next winter's project bike picked out for me already. Should be able to check alignment with some tools I can crank out on the lathe.

Heck, if worse comes to worse I could always move the good drive train from my V11 into the T3 frame. That should give 'er some giddy up.

[John A]

There is a blueprint of the tool around here somewhere, I found it from this list and made a copy but haven’t turned one yet. I thought it was on this Old Tractor but maybe not. I’ll look for my copy…

[moto]

I don't understand how a misalignment of the transmission would cause notching in the plate tangs and the drive gear. It would cause something, but I don't see why it would cause notching in particular. I am sometimes a slow student, though.