Clutch problem

Robb2013 · Jun 26, 2012

hobot said:
So, I could easily slip one of Fred's .080 steel plates in there and my friends, I think we'd be in business with a finely tuned clutch.

Click to expand...

Huh, who of ever thought : )

Well, I have this home made clutch tool and the manual makes several notes of how the damn diaphragm is dangerous and can cause serious physical injury if it's used improperly, and I have no idea how hard to crank on it before it blows up in my face or whatever it does when it kills people, so I crank it till the diaphragm loosens up and I pull the damn thing out. Yes, back on page 8 several, including yourself, made this recommendation of putting in one of OB's 080 steel plates, but when I set the diaphragm back in there I could see there was no way in hell a .080 spacer would fit. It was only when LAB told me I wasn't putting enough tension on the clutch tool that I was able to open the damn gap up to see that there was in fact ample space for an extra steel plate. What may seem very obvious to a person with extensive knowledge on a subject can be very obscure to someone with limited experience.

Hobot · Jun 26, 2012

LOL!!! Robb I went through similar novice over sights and fumbles and and online hand holding with endless teasing and badgering too. Most recent this spring, was on mere ring gaps I'd over looked on total rebuild and got away with - a few 1000 miles - then gaskets blowing and pipes smoking but nothing to do with gasket itself, ugh.

I grab my spring with a brass bowl puller and crank down till it slips right out and leave it that way in puller -indefinitely- till time to slip back in. Only a few cases of lost arms and teeth and just one decapitation reported so not much to be pensive of. I may be the only one to have a rear axle break because of spring puller letting go, but that's whole 'nother novice lesion I survived. When ya drift back on events as an old man, guess which ones will float to the top.

DogT · Jun 26, 2012

Ya, know Rob, it may have been mis-adjusted from the get go. The first time I put on my clutch tool, I just tightened up the nut enough so I could see the diaphragm was loose and that was good enough to get the clip out. Easy enough to go back on, as I remember maybe a turn or two on the nut. Yours may have been way out of adjustment and what do you know first time especially if it hasn't been working before dismantling?

All's well that ends well.

I was thinking this afternoon, if I could somehow measure the ft-lbs of the clutch when it starts slipping with different diaphragm pressures. Of course that would be static, I'm sure it's different when it's operating. And as long as it doesn't slip on the road who cares?

Dave
69S

Robb2013 · Jun 26, 2012

hobot said:
LOL!!! Robb I went through similar novice over sights and fumbles and and online hand holding with endless teasing and badgering too. Most recent this spring, was on mere ring gaps I'd over looked on total rebuild and got away with - a few 1000 miles - then gaskets blowing and pipes smoking but nothing to do with gasket itself, ugh.

I grab my spring with a brass bowl puller and crank down till it slips right out and leave it that way in puller -indefinitely- till time to slip back in. Only a few cases of lost arms and teeth and just one decapitation reported so not much to be pensive of. I may be the only one to have a rear axle break because of spring puller letting go, but that's whole 'nother novice lesion I survived. When ya drift back on events as an old man, guess which ones will float to the top.

http://www.youtube.com/watch?v=HagzTRmUBIE

Robb2013 · Jun 26, 2012

DogT said:
Ya, know Rob, it may have been mis-adjusted from the get go. The first time I put on my clutch tool, I just tightened up the nut enough so I could see the diaphragm was loose and that was good enough to get the clip out. Easy enough to go back on, as I remember maybe a turn or two on the nut. Yours may have been way out of adjustment and what do you know first time especially if it hasn't been working before dismantling?

All's well that ends well.

I was thinking this afternoon, if I could somehow measure the ft-lbs of the clutch when it starts slipping with different diaphragm pressures. Of course that would be static, I'm sure it's different when it's operating. And as long as it doesn't slip on the road who cares?

Dave
69S

There were multiple problems from the get go... that being one of them, stuck plates being another, oil contaminated plates another, crud in the gear channels another, my not understanding how the diaphragm works another... but like Hannible Smith always said, "I just love it when a plan comes together."

I'm going to enjoy pulling that clutch with my pinkie finger once I get that plate from OB. I may even post a video of it on Youtube.

DogT · Jun 26, 2012

I've run my clutch with oil on them and didn't notice any difference then when they were dry. Go figure. Yeah, I want that pinkie clutch too, I'm going to get another plate.

Dave
69S

rx7171 · Jun 26, 2012

Robb2013 said:
hobot said:

So, I could easily slip one of Fred's .080 steel plates in there and my friends, I think we'd be in business with a finely tuned clutch.

Click to expand...

Huh, who of ever thought : )

Click to expand...

Well, I have this home made clutch tool and the manual makes several notes of how the damn diaphragm is dangerous and can cause serious physical injury if it's used improperly, and I have no idea how hard to crank on it before it blows up in my face or whatever it does when it kills people, so I crank it till the diaphragm loosens up and I pull the damn thing out. Yes, back on page 8 several, including yourself, made this recommendation of putting in one of OB's 080 steel plates, but when I set the diaphragm back in there I could see there was no way in hell a .080 spacer would fit. It was only when LAB told me I wasn't putting enough tension on the clutch tool that I was able to open the damn gap up to see that there was in fact ample space for an extra steel plate. What may seem very obvious to a person with extensive knowledge on a subject can be very obscure to someone with limited experience.

OldBritts offers different thicknesses of plates starting at 0.065" and going up in 0.005" increments.
The thicker the plate the easier the pull however the thicker the plate the less clamping pressure of the clutch and increases chance of clutch slip.
In my case my clutch was a serious hand full but by adding just the 0.065" plate it is a very nice two finger pull and I've never had it slip.
OB actually offers to send you the whole set and only pay for the one you keep as long as you send back the unused ones.

Bob

Stillreel · Jun 27, 2012

I seem to be in the same boat as Robb2013.

Stack height has become the issue. It would appear that I'm 0.073" short a (measured by micrometer on each friction disc, plate and outside flange of Pressure plate = 0.9773". With 1.041 to 1.051 req'd). Measuring on the bike I get approx. 0.12" short (see below).

Complicating the issue is a mixture of plates. The PO supplied one fibre plate and 3 bronzes at 0.14 and 0.123(s) respectively. I'd like to swap out the fibre for an additional bronze but then I'm short 0.087" which will be difficult to shim out.

I just cleaned the plates (light, fine sanding) to see if that will ease the clutch slip but I fear the clutch problems have just started. Suggestions would be appreciated.

BC

dynodave · Jun 27, 2012

Stillreel said:
I seem to be in the same boat as Robb2013.

Stack height has become the issue. It would appear that I'm 0.073" short a (measured by micrometer on each friction disc, plate and outside flange of Pressure plate = 0.9773". With 1.041 to 1.051 req'd). Measuring on the bike I get approx. 0.12" short (see below).

Complicating the issue is a mixture of plates. The PO supplied one fibre plate and 3 bronzes at 0.14 and 0.123(s) respectively. I'd like to swap out the fibre for an additional bronze but then I'm short 0.087" which will be difficult to shim out.

I just cleaned the plates (light, fine sanding) to see if that will ease the clutch slip but I fear the clutch problems have just started. Suggestions would be appreciated.

BC

1.Get data:
A. thickness of each and every individual component since you have not given enough adequate identification of your clutch components . http://atlanticgreen.com/clutchpak.htm
steel clutch plates...friction plates....pressure plate.

B. depth of your basket (yes that means WITH the fall off backing plate on early clutch baskets... to top of splines.

C. You will probably need a clutch rod seal if you are leaking gear oil on plates....since short clutch stacks have very high clamping pressure and will not slip for lack of pressure.

Stillreel · Jun 27, 2012

I'll measure the clutch basket depth tomorrow.

I've taken the advise offered in this forum and installed the rod seal.

More testing tomorrow.

Torontonian · Jun 28, 2012

2 new sleeve bushes just installed ,tapped home fresh from the freezer. No need to fit the third spacer one as both were lenghthier than the originals. Small gap between the 2.Thought I would need to ream but read on another post that the mainshaft itself acts as a poor man's reamer to fit. Perfect. Also filled up motor with oil via intake valves cover to see if my oil into primary issue could be the crankseal going. This bypasses the "BODGE". Will let sit a few days.

rpatton · Jun 28, 2012

lynxnsu said:
i like this
cannot get any better
10 pages how to set a clutch oooaaaahhhhhhh..........

Yes, it can get better.

Robb2013 said:
What's next? Once I make sure the shifter is working I think I'll throw the carbs on and tie up everything on the handlbars, then buy a battery and finish up the wiring.......

Robb2013 · Jun 29, 2012

rpatton said:
lynxnsu said:

i like this
cannot get any better
10 pages how to set a clutch oooaaaahhhhhhh..........

Click to expand...

Yes, it can get better.

Robb2013 said:

What's next? Once I make sure the shifter is working I think I'll throw the carbs on and tie up everything on the handlbars, then buy a battery and finish up the wiring.......

Click to expand...

I'm trying to figure out the intent of this post... other than the obvious of course.

Torontonian · Jun 29, 2012

Clutch location circlip somewhat crushed/indented so replaced it. Basket and plates cleaned and measured for stack height and the addition of one steel towards the basket back brought plate height up to just before big circlip slot. Have both the thick and thin type outer pressure plates to choose from so chose the thinner one to fit. Can see the clutch compressor tool needed to be compressed slightly more to fit diaphram in place followed by circlip. Test it today.

Robb2013 · Jun 29, 2012

Torontonian said:
Clutch location circlip somewhat crushed/indented so replaced it. Basket and plates cleaned and measured for stack height and the addition of one steel towards the basket back brought plate height up to just before big circlip slot. Have both the thick and thin type outer pressure plates to choose from so chose the thinner one to fit. Can see the clutch compressor tool needed to be compressed slightly more to fit diaphram in place followed by circlip. Test it today.

I got my 080 plate from OB today. Put it all the way in the back. Adjusted the rod and cable... pulls nice and easy. I can't say I could pull it with my pinkie, but it doesn't take excessive strain to pull it with first 2 fingers. All bullshit aside, this was a productive thread. It pretty much addressed every aspect of what's going on with that clutch mechanism. Thanks again to all for your positive input.

Robb2013 · Jun 29, 2012

By the way.. with the extra plate in the stack, my stack height was actually a "C" hair or two higher than the outside gears, and there was still plenty of room for the circlip. When at rest, the diaphragm is flat as a pancake.

Guido · Jun 29, 2012

How thick was the extra plate?
Before you put in that plate what did the stack measure between the top of the spline and the top of the pressure plate?

Robb2013 · Jun 29, 2012

Guido said:
How thick was the extra plate?
Before you put in that plate what did the stack measure between the top of the spline and the top of the pressure plate?

My stack height without the extra plate had been between 1.050 to 1.060. The difference gap between the top of the stack and the beginning of the circlip groove was 1.20 inches. I'd mentioned that I put a .080 plate but actually it was a Barnett plate which was only 8 bucks vs 18 for the Andover. The only difference being it's .078... I figured the extra 2 thousandths wouldn't make any difference and opted to save ten bucks. Fred concurred. So there's still a little extra slop in there but I'm fine with it the way it is now.

DogT · Jun 29, 2012

Robb2013 said:
My stack height without the extra plate had been between 1.050 to 1.060.

Is this the OB method or the Dyno method, your stack height now is between 1.128 and 1.138? The OB method recommends stack height of 1.045 (750) and 1.027 (850) and the dyno recommends 1.167 (750) and 1.172 (850).

Robb2013 said:
The difference gap between the top of the stack and the beginning of the circlip groove was 1.20 inches.

I don't think 1.20", 0.120?

You will let us know if it slips? But if it's flat, according to Dyno's chart, that should be about right, as I read things.

Dave
69S

Robb2013 · Jun 29, 2012

DogT said:
Robb2013 said:

My stack height without the extra plate had been between 1.050 to 1.060.

Click to expand...

Is this the OB method or the Dyno method, your stack height now is between 1.128 and 1.138? The OB method recommends stack height of 1.045 (750) and 1.027 (850) and the dyno recommends 1.167 (750) and 1.172 (850).

Robb2013 said:

The difference gap between the top of the stack and the beginning of the circlip groove was 1.20 inches.

Click to expand...

I don't think 1.20", 0.120?

You will let us know if it slips? But if it's flat, according to Dyno's chart, that should be about right, as I read things.

Dave
69S

That was the OB method... pressure plate included. The space between top of stack with pressure plate and circlip grove before the extra plate was .120 I believe,

Right now I'm trying to decide if I should go with DOT 5 in the brake line. Lot's of conflicting stories on both sides of the fence with this.

Clutch problem

Similar threads