Clutch pack.... But what if?

'72 Commando 750.
What if the clutch pack is the proper height?
It seems on inspection the basket is full right up to the circlip.
There is no room to put in a shim. Pack height measures very close to stock measurements.
I should have written them down. My mechanic has em, I don't have em in front of me now.
I got the shim kit from Old Britts anticipating the fix for the stiff clutch pull.
My mechanic has all the literature and printouts from various sites detailing what to do.
He also says the clutch disks seem like new.
The only thing we found was the Clutch Locating Clip behind the basket was worn and broken, giving the impression of too much end play.
But once the basket was removed and we found that the main shaft is acually solid.
New venhill lined cable, properly routed. I do have low euro bars and the cable was a 57". Plenty of loop going under headlight/tank.
The actuator arm was seated correctly before disassembly and will be again when we get the clip from rabers in the mail mon/tues
Any other clues from the Gurus?

If you happen to have a spare loose handlebar or similar, mount the lever bracket on it and connect the clutch cable. Align the cable so there is no bend and pull in the clutch lever. It should be a one finger job. If it isn't, then it could be a fault with the actuating mechanism inside the gearbox cover. Many previous posts have referred to the need to align the clutch actuating lever with the route of the clutch cable as it enters the top of the gearbox cover, otherwise the cable is pulling the lever sideways as well as inwards. If the lever is properly aligned, and it is still a stiff pull, then the ball bearing that pushes against the pushrod, or the pushrod itself are not moving freely.

If the cable is a very easy pull when straight, as you bend the cable to conform to its proper position the action will get stiffer, but it shouldn't get a whole lot stiffer. If it does, then either your routing needs to be changed (you have several options on how to route it, so experiment) or the cable is duff. Don't assume that it is good just because it is new. The shallower and smoother the bends in the cable, the lighter the lever action will be.

Slacken off the adjuster on the handlebar completely. Screw in the clutch pushrod as far as it will go, and then back it off until there is a little bit of slack when you pull on the cable at the gearbox. This gives you the optimum position for the clutch actuating lever in terms of leverage and lift. Then tighten the adjuster on the handlebar.

Are the lever bracket and lever in good shape and is the pivot greased? Is your clutch pushrod the correct length?

Let us know how you get on.

Dave

Dave,
Ok I will try that route as a process of elimination for sure.
Thanks. The Clutch Locating Clip should arrive Monday (fingers crossed) or Tues.
Upon reassembly we will try that procedure. It should prove something.
I will post the results.
I have read just about every clutch thread I've found using the search.
This forum is pretty dang extensive.
It would be cool if I could actually contribute in some way.

Joe dog

Edit.....
Brand new lever, not Norton though. Its a Nissin. ( dang it *^#&^%$#!$"?"
How long is the push rod spose'd to be?

Surfdog said:

It would be cool if I could actually contribute in some way.

Click to expand...

Post results. Post pictures. All anyone can ask for.

The worse is when someone asks a question, gets an answer and doesn't let us know what happened.

Surfdog said:

Brand new lever, not Norton though. Its a Nissin. ( dang it *^#&^%$#!$"?"
How long is the push rod spose'd to be?

Click to expand...

Is the clutch lever bracket a standard Norton item? From my experience, if the distance between centres between the pivot and the cable nipple is larger than the standard Commando assembly, the lever will be a stiffer pull. I recently fitted a different bracket and lever to my classic racer. The distance between pivots on the old clutch bracket was 1.5" (from a modern Suzuki) and I replaced it with one that has centres 1.150" apart. Result: a much easier pull.

The distance between pivots (centre to centre) on my standard Commando bracket and lever is very roughly 1". (This may be a red herring if you have the standard factory item.)

The manual gives the clutch pushrod length as 9.813 to 9.803", and diameter 0.237 to 243". The ball between the clutch actuating lever and pushrod is 0.5".

As Swooshdave said, come back and let us know what you've found. It adds to our knowledge base. Pics are often useful, too! I will post a pic if that helps.

Well guys,
No Joy. Replaced the $2. Clutch Locating Clip behind the clutch basket. Clutch basket is full. No room for a shim. Pressure plate looks new from PO.
That took up what slop there was disguised as end play. Now none. Rerouted a brand new nylon lined cable (#2) 1st one was a 57" for US bars.
But I have the Euro style bars so went for a shorter cable. Lubed it up. Actuator arm is in proper position, not slipped down. Tried several different handle bar clutch levers from my "bag o levers". Still have a stiff clutch pull.

Here are some crude pics......



Daveh was commenting on the clutch perch/lever distance between the pivot and the nipple.
My levers are NOT the standard Norton '72 vintage. I see some on ebay from a '71 right now.
But there is no telling the real distances.
Any lever recommendations? i.e.: pictures, brand names and models of ones that work or have provided better easier pulls for you?

My mechanic has suggested maybe the 850 diaphram spring is a lighter pull?
But I see its the same part number on the Old Britts web pages.
He has also suggested cutting several (opposing) of the fingers off the spring to lighten the pull?
Anybody try that? At $72 a pop for a new spring seems like a last resort thing.


Still a work in progress I guess.
Thanks ahead of time.

Joe dog

If you slacken the adjuster in the middle of the clutch plate off completely does the lever/actuator arm move easily?? Is the screw/nut that holds in the roller behind the actuator arm too tight?? (I guess that the little bush in the middle of the roller is there??)

I've used various levers over the years and never really had a bad clutch pull...Magura, Tommasselli, etc....never had the supposed one finger one with 7/8" centres to see how light that really is though!

Proper Clutch pack height should leave you with approx. .050 from the clutch diaphram clip groove. you should replace a stock driver with one from your kit to achive some clearance. No clearance, no clutch. I'll bet that retainer was a bitch to put in.

Like you, I wondered if the clutch stack height was my problem. It turned out that a new genuine Norton cable, properly routed, and with the standard clutch lever and lever perch, went a long way to giving me a lighter clutch pull.

Did you do the check as Seeley 920 suggested? Also, you said you checked that the actuating lever had not slipped down, but that is not the same as checking if it is in line with the cable where it enters the top of the gearbox cover! Apologies if you have already done this. If in doubt, check out the Old Britts web page (http://www.oldbritts.com/ob_start.html) which has good pics.

Dave

Have you checked the pushrod for straightness? If its OK, apply some grease to it.

Mick

When we left our hero.......
He still had a stiff clutch pull.
After 3 different cables.
Proper routing. Good oiling of the cables.
2 different handlebar levers. (neither one Norton)
An attempt to filled basket with a shim from Old Brits.
But the basket was full right up to the circlip no room for shim.
Replaced Clutch Locating Circlip behind the basket. (have extra 1)
Called CNW for advice on possible Hydraulic Clutch mod.
Talked out of it by one of the techs there.
He sold me the "Easy Clutch Pull" kit.
Consists of shaved down pressure plate and 4 steel plates and 4 Barnett (black) friction plates.
Hopes and Confidence is high.
Appointment with Local M/C Shop for install on Friday.
I hope to attend the festivities. (even if it costs more to watch).
Any wagers on the outcome?
Choices:
A. still have stiff clutch
B. new lighter pull clutch
C. Clutch slips and drags all over the place.
Obviously I'm going with B.

Joe dogg

I do not believe the clutch pack should come to the lip of the circlip. Swap out a stock driver for one of the shim drivers to bring the clutch pack height down. Up to .050 clearance between the pack and the groove should be attained. Give it a try.

Please let us know how things go Surfdog, I need to do something as mine is fairly stiff & my left elbo hurts so bad I can't even pull my clutch in at all right know. Missing a few group rides and hating it. Thinking of the hydrolic conversion. Why did the CNW tech talk you out of it? And is it really a lot easier to pull?

My understanding of the clutch operation is; with the lever released, the spring should be just 'popped' over centre, holding the pack in place; the further away from this point, the harder the clutch pull.
Not sure if getting the pack up to the circlip groove is important, or the interface between where the spring acts against the hub? It seems to me that this is the actual pivot point, or more specifically, where the circlip lines up relative to the hub. If the hub isn't solidly mounted in its intended location no correction of the pack height would be properly effective?

I was evidently fortunate in just throwing all the old stuff back in (bronze plates) , and I've got a clutch that I thought wouldn't hold, as it felt far too easy.
As things turned out it works as it should, so I've never had to do any experimenting to get it right. Seems I was just lucky this time!

Hey guys,

gtsun said:

Please let us know how things go Surfdog, I need to do something as mine is fairly stiff & my left elbo hurts so bad I can't even pull my clutch in at all right know. Missing a few group rides and hating it. Thinking of the hydrolic conversion. Why did the CNW tech talk you out of it? And is it really a lot easier to pull?

Click to expand...

We did not 'talk him out of ' the hydraulic clutch but rather gave him an option that may to address his stiff clutch pull that is a bit less involved. The hydraulic clutch is fantastic and extremely smooth but it may not transform a hard clutch enough for some. The smoothness certainly takes care of those forearms going numb after riding for a while but it's my opinion that you need to have everything else just right in your clutch before going to the Hydraulic set up to get maximum results from it. Once the clutch works as well as it can then adding the hydraulic system to it changes what you thought a Commando clutch would ever feel like.



Matt
Colorado Norton Works

Hey guys,
Matt's 100% correct.
I guess I worded that earlier post a bit too literally.
I should have said I was guided by the helpful guys at CNW towards getting the clutch right first before considering the Hyd. Clutch.
The attempt at install of the easy pull from CNW is now slated for Tues. the 15th coming up.
I will be reporting in as to how it goes. This fix certainly seems like valid attempt to address my problem and the woes of others who frequent these pages.
Fingers crossed and confidence is high.
Thanks again
Joe aka surfdog

When we left our hero he was taking his Commando to the only bike mechanic in the area with enough experience to work on vintage British Bikes.
Early this morning I dropped the machine off. Gave him the speech about the CNW easy pull clutch kit, how the pressure plate had been shaved down a bit. And how when he had it opened up, if he would call me and I could come and see the guts and compare the 2 piles of plates for myself etc etc.
I got the call and rushed over to find 2 neatly stacked piles of clutch plates and compared the 2 pressure plates.
Indeed the CNW shaved one was a bit thinner and ready to go. New Barnett plates and the other plates ready to go back in.
I gave him the thumbs up and fingers crossed salute.
I finally got around to getting off work and picking up the bike. He had called and said I would be happy because it WAS an easier pull now.
And so the saga ends! With only about 15 test miles on her before I parked her at home, I was pleased.
No its not a 2 finger clutch, nobody ever promised that. But it is easier to pull and a pleasure to be able to slip the clutch when needed.
Before it was all or nothing just about, and required the use of a gorilla's grip. She pulls strong with no sign of slippage.
I can't wait to put some real miles on her to get the real feel of the clutch now.
I'm stoked. I can't exactly say what the difference was between the 2 piles, but I tend to feel the height of the new pack is SHORTER than what was in there to begin ths ordeal. As I indicated in my earlier posts and pics the spring was nudged right up to the edge or the circlip.
Heres to CNW for getting me off the gorilla/carpal tunnel syndrome type grip.
Thanks guys I highly recommend this pathway.
As for adding the hydaulic clutch kit, for now I'm satisfied with what I got.
NEXT UPGRADE: possible front stainless rotor for my AP/Norvil Racing caliper.
Chime in when needed boys, thanks to all.

Try backing off the adjustment in the center of the clutch and taking up the difference at the cable. This sets the actuator arm at a less acute angle and should relieve the pull pressure somewhat.

pvisseriii said:

I do not believe the clutch pack should come to the lip of the circlip. Swap out a stock driver for one of the shim drivers to bring the clutch pack height down. Up to .050 clearance between the pack and the groove should be attained. Give it a try.

Click to expand...

Was this the issue? I do not mean to blow my horn( maybe I am) but I just wanted to make sure I wasn't full of shit on this.

pvisseriii,
I did not do the work.
I only saw that that the new pressure plate was thinner, so I'm assuming it wasn't as tight to the circlip as original before he started the swap.
He (my mechanic) also said that, yeah, it didn't come up in height all the way as before too.
From looking at the old britts article, I assumed by "adding" a shim plate it would bring the pack height up.
However, now I'm considering that maybe it just meant to swap out one of the plates for a thinner one therefore decreasing the stack height.
I think your horn is tooting for sure. beep beep.
But the (mis)understanding for me in all the articles and posts was to INCREASE the stack height.
Thats what happens when you "add" a shim.
Whereas if you swap out a plate for a thinner one the height would decrease, correct?
Now since I had sent the shim kit back to old brits for a refund because we couldn't "add" a shim to the already full stack as suggested in the article.
And it was impossible to do what you were suggesting. Even though that ended up being the answer in a round about way.
To recap: The CNW easy pull kit consists of 4 plain and 4 barnett friction plates plus the shaved down pressure plate.
Its easier now thats basically all I really know and the stack height mystery rolls on.
jdogg