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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => Project Custom Motobricks => Topic started by: pallum on September 22, 2013, 02:26:50 PM

Title: The K75 Wet Clutch
Post by: pallum on September 22, 2013, 02:26:50 PM
(http://i.imgur.com/kn68EwDl.jpg)
Title: Re: Coming soon...
Post by: johnny on September 22, 2013, 02:48:23 PM
cherry bomb... do it...

j o
Title: Re: Coming soon...
Post by: TimTyler on September 22, 2013, 03:16:29 PM
Sealant is not necessary on the front end of the transmission housing.

What's that bolt for?
Title: Re: Coming soon...
Post by: Scott_ on September 22, 2013, 04:13:04 PM
Quote
What's that bolt for?

I was wondering the same thing....... :dunno
Title: Re: Coming soon...
Post by: johnny on September 22, 2013, 04:28:48 PM
thats a external grubb screw adjuster... comes with lifetime warranty on the internal worm gear...

j o
Title: Re: Coming soon...
Post by: Scott_ on September 22, 2013, 04:36:05 PM
thats a external grubb screw adjuster... comes with lifetime warranty on the internal worm gear...

j o

or an access hole............. :yow
Title: Re: Coming soon...
Post by: johnny on September 22, 2013, 04:40:42 PM
pallum gotts him a glory hole... better getts some lube... and a moto stand...

j o
Title: Re: Coming soon...
Post by: pallum on September 22, 2013, 09:08:02 PM
This, fellow brickers, is the beginning of my K75 wet clutch setup. First problem has been encountered-- more info when I get around it.
Title: Re: Coming soon...
Post by: wmax351 on September 22, 2013, 11:18:21 PM
This, fellow brickers, is the beginning of my K75 wet clutch setup. First problem has been encountered-- more info when I get around it.


But why? Haha.



Title: Re: Coming soon...
Post by: argent brick on September 23, 2013, 11:13:05 PM
A wet clutch on a K75? This should be good....
Title: Re: Coming soon...
Post by: TimTyler on September 23, 2013, 11:16:19 PM
This is the sort of thing Tennessee moonshine will do to a once perfectly sane motobricker.
Title: Re: Coming soon...
Post by: Opus on September 24, 2013, 08:32:34 AM
Tim,
He is in middle TN. Moonshine is a East TN. thing.
Middle TN is more into Jack and beer.

Good Luck with the Project Pallum!
Title: Re: Coming soon...
Post by: pallum on September 24, 2013, 06:24:34 PM
Why? I f***n hate pulling the transmission :P But other than that I kinda just want to see if it's possible. Ran into a huge leak from the intermediate housing, but I just started a new job so progress won't be nearly as fast as I thought. I'll keep the updates coming!

And no, no alcohol was harmed in the creation of this project...
Title: Re: Coming soon...
Post by: wmax351 on September 24, 2013, 08:01:44 PM
Are you using the oilproof clutch from siebenrock?
Title: Re: The K75 Wet Clutch
Post by: pallum on October 11, 2013, 10:18:52 PM
So I finally got time to mess around a bit and I'm close-- but it's a complicated process.

I chose to have a spare clutch disc relined in kevlar from H&R clutch, grooved as per their recommendation. Had it back within a week and the clutch material seems to be holding. I went for a clutch made to be used in oil, rather than an "oil resistant" clutch simply because oil contamination isn't a risk, it's the point-- I wanted to be sure to have the best shot at this going into it I can. (Plus the Seibenrock always seems to be out of stock)

Speaking of oil: I went with 10W-40 Mobil diesel oil for the intermediate housing. The recommendation of H&R was automatic transmission fluid but in hopes of minimizing engine and transmission contamination if there is any fluid transfer I went with the diesel for compatibility (I go one engine oil change on diesel at the beginning of each winter anyways just because the "added detergents" make me feel good, superstitions aside...)

So what I hadn't counted on was the sheer violence and air expansion inside the new intermediate housing environment. The first attempt showed an almost immediate leak around the plastic "padding" (as BMW calls it) at the top of the transmission mating surface just next to the starter. It wasn't super surprising, considering I hadn't sealed that piece in there all the way but it was enough to allow me to test the clutch on the road.

After removing the transmission/swingarm/final drive/wheel as one unit (with a sledgehammer to break the sealant...) I whipped up an "air release fitting" as I call it on the lathe at school:

Full res: http://i.imgur.com/LON3OXY.jpg (http://i.imgur.com/LON3OXY.jpg)
(http://i.imgur.com/LON3OXYl.jpg)

It's not perfect, but I'm not a machinist-- and yes it came out of that 2" aluminum, it's what I had on hand  after making a modified fixed swingarm pivot pin... (http://i.imgur.com/Wu0e2zK.jpg)  :falldown:
So the nipple is sized so that a 1/4" ID vinyl tube would fit snugly over it (about .3") and there is a 3mm hole drilled from the nipple almost to the bottom of the piece. The bit at the end was ground off so that it would fit into the plastic "padding" from earlier and the threads were approximately 1/4x20 (no metric lathes at school). I did this freehand so never drew any official drawings for it. After threading it all the way through the plastic padding I used a dremel to open a small slot in the threaded portion of the shaft which would be inside the intermediate housing and act as the air release path through the 3mm internal hole (and of course I forgot to take pictures of this too...). I faced the slot to the rear of the bike to hopefully keep as much oil out of this new air release as possible and attached my hose:

Full res: http://i.imgur.com/us2r4vC.jpg (http://i.imgur.com/us2r4vC.jpg)
(http://i.imgur.com/us2r4vCl.jpg)
Ignition coils on left, starter body on right

Well, air gets out. But so does oil-- so much so that it left a nice trail around the neighborhood. I've thought about trying to shield the air release port from oil on the inside or possibly running the transmission without its input shaft seal to allow the intermediate housing to vent through the transmission, but they're only ideas and I'm kinda out of time on this project. I'll be reverting back to the dry setup next weekend until I get another chance at working on this.

Unless you guys have any ideas, please share!


Title: Re: The K75 Wet Clutch
Post by: wmax351 on October 12, 2013, 04:15:32 AM
Yeah, usually wet clutches are lower speed, multi-plate affairs. Very smooth edges, on a basket type setup. Dry clutch is a very different engineering plan, and it is more than just the difference between being in oil and not.


Wet clutch bikes have a primary drive reduction. Usually 1:2 at least. They also aren't submerged entirely. Just bathed in part.
Title: Re: The K75 Wet Clutch
Post by: pallum on October 26, 2013, 01:00:46 AM
http://i.imgur.com/qcdCnLI.jpg (http://i.imgur.com/qcdCnLI.jpg)
(http://i.imgur.com/qcdCnLIl.jpg)

http://i.imgur.com/JbazkvC.jpg (http://i.imgur.com/JbazkvC.jpg)
(http://i.imgur.com/JbazkvCl.jpg)

http://i.imgur.com/i0btZUL.jpg (http://i.imgur.com/i0btZUL.jpg)
(http://i.imgur.com/i0btZULl.jpg)

http://i.imgur.com/Dmd5Xyw.jpg (http://i.imgur.com/Dmd5Xyw.jpg)
(http://i.imgur.com/Dmd5Xywl.jpg)
Title: Re: The K75 Wet Clutch
Post by: enb54 on May 20, 2015, 07:48:16 PM
So, I am guessing that the "wet clutch" didn't quite live up to expectations?... Just curious...
Title: Re: The K75 Wet Clutch
Post by: enb54 on May 20, 2015, 09:02:35 PM


So now I'm really curious... Got any more information?
Title: Re: The K75 Wet Clutch
Post by: pallum on May 22, 2015, 01:17:42 AM
From the initial tests I could tell that engine power was down, but I would probably ride it anyways as I'm a rider for distance, not speed. This was all done in TN, and after a move to WA I do still have all the old pieces but not the time to keep at it right now. The plan is still off and on in my mind, but nothing concrete is happening. Still trying to think of a way to vent the clutch chamber without losing all my oil at the same time. Still thinking about running sans transmission input shaft seal, I'm sure there's another fairly easy solution somewhere out there but I just haven't had the time to do any more serious research.

Still rolling around dry-style for now. Just got a new K75, trying to get it up and into shape this weekend. (25k miles and it's never even had the footpegs removed--- completely unmolested  :2thumbup: ).