Clutch problem

Clutch problems.........Dot 5 brake fluid? have you been winding us up :?: 14 pages on a clutch pressure spring set up...come on.

As someone has said, this horse has been beaten. I would suggest that you start a new thread for a new topic. Don't get me wrong, there is actually some good info in this thread and some things were cleared up with measuring stack height based on different methods. It just took a long ride to get around this block.

john robert bould said:

Clutch problems.........Dot 5 brake fluid? have you been winding us up :?: 14 pages on a clutch pressure spring set up...come on.

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Yeah, I'm winding you up. Doesn't seem like that's a very hard thing to do. Was someone there bending your arm forcing you to read these 14 pages? Curious... I only remember one post in there by you, where you ascertained the obvious. You seem put out. Exactly how were you put out by all of this?

drones76 said:

As someone has said, this horse has been beaten. I would suggest that you start a new thread for a new topic. Don't get me wrong, there is actually some good info in this thread and some things were cleared up with measuring stack height based on different methods. It just took a long ride to get around this block.

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I' ve just been answering a couple last questions people have asked. Dave and Guido gave a lot of input, thought they at least deserved responses to their questions.

Hey guys, and you know who you are, Do you all realize that 2 weeks ago Rob was oblivious to the intricacies of the Norton clutch and now he is an expert compared to most.


Rob, I think you need to get some info on crank pressure, erroneous leaks and the benefits and proper locations of crankcase breather valve. This topic could also flow seamlessly into wetsumping discussions.

Rob, those who care are proud of your successes. Salute

What he said ^

pvisseriii said:

Hey guys, and you know who you are, Do you all realize that 2 weeks ago Rob was oblivious to the intricacies of the Norton clutch and now he is an expert compared to most.


Rob, I think you need to get some info on crank pressure, erroneous leaks and the benefits and proper locations of crankcase breather valve. This topic could also flow seamlessly into wetsumping discussions.

Rob, those who care are proud of your successes. Salute

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dirtymartini said:

What he said ^

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Thanks guys. These two comments meant a lot to me. When the extra plate from OB came in the mail, ten minutes later, the clutch was assembled and adjusted correctly. I obviously learned something. The next newbie who comes along with no knowledge on this clutch can read through this thread and he will be an expert by the time he's done reading also.

Crank pressure, leaks, electrical items not working... it's all coming. This bike is pretty much reassembled. Now the real problems will surface. 20 years ago, someone stopped riding this bike for a reason. I hope it was because PO's wife got pissed at him for not spending enough time with the kids.

rob, hopefully we all learn something from this forum. there are a lot of experts out there, and there are a lot of egos as well. when you have an expert ego thrown in the mix, you don't get information, just opinioins. don

I've had my 2 Nortons for about 35 years now. I always assumed the clutch was a hard pull from the factory and maybe it was. Not anymore
I have always been plagued with leaks too.
It wasn't until these last 3 years and since joining this site that I have become an "expert" of my own bikes.
With the help of this forum and Phil @ Fair Spares, Bob @ Rabers and the many others out there I have got my bike to run so reliably, smooth and worry free.

Robb, you know your clutch setup now, when it comes to any head leaks we'll be ready for you as I have totally cured mine.

Guido said:

I've had my 2 Nortons for about 35 years now. I always assumed the clutch was a hard pull from the factory and maybe it was. Not anymore
I have always been plagued with leaks too.
It wasn't until these last 3 years and since joining this site that I have become an "expert" of my own bikes.
With the help of this forum and Phil @ Fair Spares, Bob @ Rabers and the many others out there I have got my bike to run so reliably, smooth and worry free.

Robb, you know your clutch setup now, when it comes to any head leaks we'll be ready for you as I have totally cured mine.

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That's good to know Guido, thanks. Having this deep well of knowledge to draw from is the most valuable tool in a guy's tool kit.

OK, I'm finally getting around to adding a Barnett plain plate (0.078") in my clutch pack. Turned into a 1 finger clutch, but we'll see if it slips. I can now see why no one was feeling the compound bow effect. Apparently that only happens when you have a stiffer than 1 finger clutch. I don't feel that effect now. I've got a slight bow to the outside with the diaphragm now, not pulling on the clutch. I think it was nearly flat before the extra plate.

I had to tighten up the clutch tool to get the diaphragm to go into place and install the spring, otherwise the diaphragm just wanted to go into the spring groove. Now the adjuster stud is nearly flat with the locking nut and the adjustment is not so critical.

Dave
69S

I'm thinking it's going to slip. I can't tighten the adjuster nut without the clutch slipping and I'm nowhere near the torque needed. I guess I'm going to have to get the pack from OB again. I guess I could measure the pack height, at least the Barnett plate didn't set me back much.

Dave
69S

Clutch pack height, dynodave method = 1.185, OB method = 1.068, within the realm of measurements. So pack height is already larger than required. The diaphragm spring is flat when I put my original parts in, and deflected 0.1" to the outside when I install the extra barnett clutch. I just don't get it, but it seems to want an extra plate less than .078" and the thinnest OB has is .060.

According to dynodave's chart a flat diaphragm is good, and if it's .1 over, I've gone past flat to the nearly weakest part of the diaphragm curve.

Why is my bike so different than everyone else's?

Dave
69S

DogT said:

...

Why is my bike so different than everyone else's?
...

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Even though mine is a MK3, I have the same issue. I've been thinking of picking up a set of older & nominally thicker clutch discs and swapping in one or two.

DogT said:

Why is my bike so different than everyone else's?

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I doubt it is.

I think what you may have overlooked, (and what the dynodave and OB information completely fails to mention) is that altering the stack height by a factor of "x" will result in a "2x" change in spring deflection because the height change is applied at the "half radius" positon of the spring (where the spring rests against the pressure plate), therefore adding an extra 0.080" plate will deflect the spring by 0.160"

OK, I measured my clutch stack height and it's right at 1.179 by the dynodave method, which is 12 thou over stock. Can't figure that, but there it is, I tried several methods, and it always comes out at about that number. It's my fiber plates that seem high, the total of the plates is .594 which gives an average of .1485 for each plate. The diaphragm is right at flat with my stock plates and the clutch engaged. With the Barnett plate in, it's over flat by .1 or more.

Anyhow, I've ordered dynodave's seal and am hoping that when I get the oil off the plates and install everything, maybe it won't slip with the reduced pressure, but I'm not convinced that the Barnett plate at .078 is not too much because with it, the diaphragm inverts too far and doesn't automatically return. I may have to get a thinner plate from OB.

I did re-read dynodave's page about 10 more times and am finally getting to understand the relation between what he calls deflection and where the pack height is. It's too bad he didn't put in his chart the deflection from flat and also pack height because he references both in the paragraphs. He doesn't explicitly state where the stack height is as standard vs. deflection, one has to read it into the chart which is rather difficult for me. It would be real easy to add the stack height and deflection from flat in the chart right along with total deflection.

Dave
69S

DogT said:

OK, I measured my clutch stack height and it's right at 1.179 by the dynodave method, which is 12 thou over stock. Can't figure that, but there it is, I tried several methods, and it always comes out at about that number. It's my fiber plates that seem high, the total of the plates is .594 which gives an average of .1485 for each plate. The diaphragm is right at flat with my stock plates and the clutch engaged. With the Barnett plate in, it's over flat by .1 or more.

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In fact, the OB information does show the simplest method.


If the diaphragm spring is set to dead flat and held in position with the plates installed, the distance from the edge of the spring to the circlip groove is the additional amount required to set the stack height to the "flat spring" position.

Back on p.8 of this thread :shock: , dynodave stated that the sweet spot of the spring is 0.030" beyond flat. If 0.015" is added to the "flat spring" packing dimension, then that should result in the spring being set 0.030" inverted (outwards).

L.A.B. said:

Back on p.8 of this thread :shock: , dynodave stated that the sweet spot of the spring is 0.030" beyond flat. If 0.015" is added to the "flat spring" packing dimension, then that should result in the spring being set 0.030" inverted (outwards).

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He says that in his clutch page too. I just hadn't thought about doing what your suggesting. I guess that's why we're here. No way can I read those little marks on the scale, I'll see if I can find a washer that will match the distance and see what I come up with.

Dave
69S

DogT said:

No way can I read those little marks on the scale

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Fit the circlip, then measure the gap between the spring and circlip with feeler gauges?

That's what I was thinking or finding a washer that will fit in the space, my feelers only go to .25, but if I add them all together.... Thanks.

Dave