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M8 Clutch Question

Started by markymark, April 08, 2019, 04:10:06 PM

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markymark

Had a chance to demo all the new 19 models with the hydraulic clutch. One thing I noticed was on downshifting, there is a distinctive bang/click through the clutch lever. Anyone else notice this ?

stro1965

Mine does it. I've heard that it's rare to have an M8 that doesn't do it.

Tynker

My '17 Ultra Trike did it for about the first 1000 miles, then it went away. It never did it again.
Earl "Tynker" Riviere

markymark

Just wondering what is causing the feedback through the hydraulic system.

cmashark

Probably because the pushrod goes through the main shaft and bounce is felt through the fluid.
2021 FLHXSE

Tynker

Earl "Tynker" Riviere

fleetmechanic

I rode a '19 police model last week and it was my first trip on an M8.  The clutch lever feedback is the thing I noticed the most.

Buglet

   I install a baker Hydraulic Side Cover door on one for other reasons all I can say it is a total different bike to drive, no more clunking in gear, you can find neutral, shift better then ever, and no clutch lever feedback. It is about 5% harder to pull in.

fleetmechanic

April 19, 2019, 03:37:53 PM #8 Last Edit: April 19, 2019, 03:42:09 PM by fleetmechanic
One of our riders bought a new RG in '18 and he told me yesterday that his clutch had a lot of this feedback but after some miles were put on that it went away.  Maybe he just doesn't notice it any more.

Maddo Snr

April 23, 2019, 01:51:19 AM #9 Last Edit: April 23, 2019, 02:07:35 AM by Maddo Snr
Its my view that the M8 'clutch clunk' is associated with the unvented void between the s/c diaphragm face and the casting surface of the trap door. Oil seals up this space as the s/c piston moves and then a vacuum exists as the lever is returned. the area then vents suddenly causing the 'snap action'

A 1/8" bleed hole in the casting mating surface in front of the diaphragm cures it, as does the AIM s/c.

Remember, the Moco are on their FOURTH! :emsad: version of the s/c diaphragm. The whole show is a debacle.
2018 FLHX 107
Rinehart 45s, SE cleaner, TTS MasterTune. 92/108

Harley Pilot

"A 1/8" bleed hole in the casting mating surface in front of the diaphragm cures it"
Maddo Snr, the hole needs to be drilled in the slave housing,or end cover?

Thanks,
Dan.

Admiral Akbar

Quote from: Maddo Snr on April 23, 2019, 01:51:19 AM
Its my view that the M8 'clutch clunk' is associated with the unvented void between the s/c diaphragm face and the casting surface of the trap door. Oil seals up this space as the s/c piston moves and then a vacuum exists as the lever is returned. the area then vents suddenly causing the 'snap action'

A 1/8" bleed hole in the casting mating surface in front of the diaphragm cures it, as does the AIM s/c.

Remember, the Moco are on their FOURTH! :emsad: version of the s/c diaphragm. The whole show is a debacle.


:teeth:  Good one

rbabos

April 23, 2019, 10:20:38 AM #12 Last Edit: April 23, 2019, 05:34:11 PM by rbabos
If you guys are running a slip/assist clutch, the feed back on the leaver is from that. You should feel the buzz on a v rod clutch if you put too much load in too tall a gear at low rpms. If you look at how it all works, it's perfectly normal. It can also be from in the case of the big twins,  the helical gear set and poor main shaft end play control slamming the pushrod against the slave.
Ron

Maddo Snr

Quote from: Harley Pilot on April 23, 2019, 05:41:01 AM
"A 1/8" bleed hole in the casting mating surface in front of the diaphragm cures it"
Maddo Snr, the hole needs to be drilled in the slave housing,or end cover?

Thanks,
Dan.

The cover Dan, I'm out bush on the FLHX at the present. I'll post a pic when I get home.

The hole lines up with the milled area in the other side to ensure the void drains, just drilling a hole wont solve anything because the other side is fluid-filled in OEM form.
2018 FLHX 107
Rinehart 45s, SE cleaner, TTS MasterTune. 92/108

Harley Pilot

"The cover Dan, I'm out bush on the FLHX at the present. I'll post a pic when I get home"

Thank you,

Admiral Akbar

Quote from: rbabos on April 23, 2019, 10:20:38 AM
If you guys are running a slip/assist clutch, the feed back on the leaver is from that. You should feel the buzz on a v rod clutch if you put too much load in too tall a gear at low rpms. If you look at how it all works, it's perfectly normal. It can also be from in the case of the big twins,  the helical gear set and poor main shaft end play control slamming the pushrod against the slave.
Ron

:up: :up: :up:

Maddo Snr

Quote from: Admiral Akbar on April 23, 2019, 08:11:21 AM
Quote from: Maddo Snr on April 23, 2019, 01:51:19 AM
Its my view that the M8 'clutch clunk' is associated with the unvented void between the s/c diaphragm face and the casting surface of the trap door. Oil seals up this space as the s/c piston moves and then a vacuum exists as the lever is returned. the area then vents suddenly causing the 'snap action'

A 1/8" bleed hole in the casting mating surface in front of the diaphragm cures it, as does the AIM s/c.

Remember, the Moco are on their FOURTH! :emsad: version of the s/c diaphragm. The whole show is a debacle.


:teeth:  Good one

The 'click' at the lever I'm talking about is hydraulic Admiral. The bikes do it when stopped/engine dead. Many KTM EXCs with Brembo slaves do it as well.

I've ridden lots of different '19s and never felt a '19 do anything other than a buttery smooth down (and up) shift. Technique maybe?
2018 FLHX 107
Rinehart 45s, SE cleaner, TTS MasterTune. 92/108

Harley Pilot

Quote from: Maddo Snr on April 23, 2019, 04:35:04 PM

The cover Dan, I'm out bush on the FLHX at the present. I'll post a pic when I get home.

The hole lines up with the milled area in the other side to ensure the void drains, just drilling a hole wont solve anything because the other side is fluid-filled in OEM form.

I'll be doing both (the milling and drilling the hole) I'm not confident enough in the vent tube to rely on that fixing the problem!

Thermodyne

The M8 clutch uses a ramp between the pressure plate and the basket.  So under power the ramp tightens the clutch and under decal the ramps push the plate out and slip the clutch.  Slipper clutch.  The pressure plate rotates a little between the ramps.  It actually has wear pads under the springs.  And because the release system is always at 0 lash, it transfers the little slap from pulling to decal and well as the slight outward movement of the plate. 

You can see the ramps here



And here



The pressure plate actually carries one friction plate and one steel.  Makes it a little tricky lining the plate up as you set the plate into the ramps. 

Admiral Akbar

Quote from: Thermodyne on April 26, 2019, 06:05:51 PM
The M8 clutch uses a ramp between the pressure plate and the basket.  So under power the ramp tightens the clutch and under decal the ramps push the plate out and slip the clutch.  Slipper clutch.  The pressure plate rotates a little between the ramps.  It actually has wear pads under the springs.  And because the release system is always at 0 lash, it transfers the little slap from pulling to decal and well as the slight outward movement of the plate. 

You can see the ramps here



And here



The pressure plate actually carries one friction plate and one steel.  Makes it a little tricky lining the plate up as you set the plate into the ramps.

TFF,    :teeth:

You can't see the ramp itself as it is on the opposite side of some metal boss.

Admiral Akbar

Quote from: Maddo Snr on April 25, 2019, 03:58:11 PM
Quote from: Admiral Akbar on April 23, 2019, 08:11:21 AM
Quote from: Maddo Snr on April 23, 2019, 01:51:19 AM
Its my view that the M8 'clutch clunk' is associated with the unvented void between the s/c diaphragm face and the casting surface of the trap door. Oil seals up this space as the s/c piston moves and then a vacuum exists as the lever is returned. the area then vents suddenly causing the 'snap action'

A 1/8" bleed hole in the casting mating surface in front of the diaphragm cures it, as does the AIM s/c.

Remember, the Moco are on their FOURTH! :emsad: version of the s/c diaphragm. The whole show is a debacle.


:teeth:  Good one

The 'click' at the lever I'm talking about is hydraulic Admiral. The bikes do it when stopped/engine dead. Many KTM EXCs with Brembo slaves do it as well.

I've ridden lots of different '19s and never felt a '19 do anything other than a buttery smooth down (and up) shift. Technique maybe?

Got you the first time..

Clutch changed on the 19s. I'll take your word but will verify. Maybe it's the reason for the no clunk?


wolfmotor1

My 2019 FLHRXS does it.  Feedback thru the clutch feels weird and the shift to second is louder than any of the Harleys I've had over the years.

HarleyHiwayMan

My 18 Limited does it. And the shift down from 3rd to second is brutal. The bike has 1100 miles and seems to be getting better.
BTW, I bought it May 1, old new stock - it's 12 days used.
Flatland Charley, Lazy Photographer
Ride with an attitude!!

TXHogrider

Mine does it as well.  I just bought a 2019 Street Glide Special and I am not liking the feedback through the clutch lever on every down shift.  It is hard to find neutral, and both of my twin cams shift up (and down) smoother than this thing does.