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Discussion Starter #1
Hi All I'm after a bit of technical help
I have just completed the build of a TR6 66 engine to put in my 69 T120 frame
This was the biggest project that I had done, probably a bit out of my technical league

Took it out for it's first spin round the block
Pull clutch fully in and it grinds a lot when going into first gear, does actually go through the gears well
Cannot get neutral (can find it easy when stopped)
Feels like the clutch is still biting and trying to pull me forward when clutch is pulled fully in

When stopped and I pull the clutch fully in a try the kickstart it is totally free showing that the clutch plates have parted
Adjusted the clutch adjuster through the primary case so bites about half way
Pull in kickstart moved freely, let out kickstart bites and starts the engine

But still grinds into gear, cannot find neutral and still pulls forward slightly when clutch fully in???

Removed the gear oil 80w in case the drag was there but still the same

Any ideas where I should be looking or what I can try

Cheers
Ade
 

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Hi, Ade: When you mentioned that you set the clutch adjustment screw "about half-way out", did you mean 1/2 turn back from just touching the rod, or half way out on it's thread. It should only be 1/2 turn out from touching, with the cable backed off and loose. Just a thought.
Hope this helps: Jim
 

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Do you have the correct clutch operating mech in the cover, for 66 this should have a little spoke that protrudes through the screw in abutment in the top of the cover allowing the cable to be attached without removing the cover. You would also need a 66 cable to match. Assuming both these parts are correct you need to ensure that the spoke can move freely in the abutment and is not binding part way up. I have needed to run a drill through in the past.

Rod
 

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Discussion Starter #4
Thank you for all your help

Just to clarify, when I said "Adjusted the clutch adjuster through the primary case so bites about half way"
That's adjusting the Adjuster pin at the end of the push rod until the handlebar clutch level bites about half way
BUT
Just removed the primary case cover and removed the plates
I have about 3/8" movement on the clutch basket !!!
Something either did not tighten up correctly or has moved

Will try and get the clutch securing nut off tomorrow night
 

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The clutch basket does float quite a lot.You do seem to just have a dragging clutch so a bit more adjusting and running the surface off the new plates a little.
 

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First, can you confirm what I asked earlier?
Second, you are adjusting that centre screw incorrectly?
Third, how are the clutch springs adjusted?
Fourth, do you have 3/8 in and out movement, is it just the basket or does the main shaft move with it?

Rod
 

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Hi Ade,
First thing to say is what a stunning bike, it looks beautiful.

The Triumph/BSA clutch is just rubbish, mediocre if you are being kind.
That 3/8 play on e clutch basket - that is normal, Triumph/BSA decided that was an acceptable running clearance, so please do not worry too much about it.
The clutches apear to fall into two camps, ones that kind of work OK, and ones that are complete bitches. The difficult thing is no one seems to have a incite into what causes one to work and another to be a nightmare.I certainly do not have a clue.

I think first you should check your setup again, just in case.

This is how I do it, others might have different methods that work.
A) First as Jim said, make sure the cable is completely slack, I would go as far as removing it from the clutch lever.
B) Next unfortunately you have to have the primary cover off again.
C) Make sure the clutch springs are not too tight and coil binding, adjust them so the tension nuts are flush or just proud of the clutch pressure plate (I am assuming the pressure plate is not distorted and there are no notches in the clutch drum caused by the plates, if you are not sure strip the clutch and check).
D) This is a little unusual, but it works for me-screw in the central adjuster until the cover has lifted and the plates are free.
E) Spin the kickstarter With first gear engaged--observe the clutch pressure plate spining, it should not 'wobble' if it does adjust the clutch spings until there is no 'wobble'. A pointer made out of a bit of wire helps to judge the movement.
F) now back off the central pushrod adjuster so the clutch pressure plate clamps the clutch together, and keep turning so you know there is clearance.
G) carefully screw in the adjuster until you can feel the clearance is 0, this can be difficult to guage as there is light contact at first, when you have established the point the pushrod and ajuster touch, back off the screw 1/2 a turn to give running clearance.
H) Re-attach your cable and adjust it for the smallest clearance you can get away with, remember to check on both locks as well as with the bars straight ahead.
I) Try the lever if it is excessively hard to pull, then the springs might be too tight (always look out for coil bind), you might need to slacken them slightly by the same amount , you can check if you have introduced 'wobble' on the pressure plate but just holding the clutch lever in and turning the clutch with the kickstart, if you have introduced 'wobble' I am afraid it needs to be eliminated.
The spring tension is a balancing act between alight pull on the lever and clutch slip. I tend to start light and increase the pressure in increments- unfortunately every adjustment means removing the primary cover.
I) refit the primary cover and with the recommended amount of appropriate oil, if it is a good clutch most oils will work, if it is a 'bitch clutch' non will.
H) Take her out fo a ride, if you are lucky first gear will easily engage and you will find neutral every time you need it.

As I said earlier, this is the adjusment method I am happy with, it is not exactly the same as the factory manual.

If the clutch is still unsatisfactory, then I recommend a 7 plate conversion, this seems to sort this problem out in most cases.
I personally would never consider a 6 plate clutch and always replace them with 7 plate conversions, but others have run happily for years on 6 plate clutches.

Best of luck

Regards
Peg.
 

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Discussion Starter #8
Hi Red
My Clutch does have the spoke and abutment, cable clips in from above
3 clutch spring adjusted equally, wound in until the tension felt right on the handlebar clutch lever, not scientific I know.
Main shaft does not appear to move, it is as if nut is no longer tightened enough
I'll be checking tomorrow once I have welded up an old clutch plate to hold the clutch centre

Hi Peg
I think the clutch play is excessive, I'll check the clutch securing nut tomorrow
My drive plates look fine, Once I've rebuilt I try and set up as per your instructions

Cheers
Ade
 

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Ade,

Having checked that both sides of the main shaft are secured. Ensure that the spoke assembly can move freely through the abutment, the bore is stepped and the spoke can jamb up reducing available travel. Also make sure you have the right cable, I'm pretty sure the 68 on cable has a longer inner.

When you come to adjust the clutch slacken the cable completely, and give the the end of the clutch push rod a wee tap to make sure the balls in the lifting mech have seated. Adjust the three springs till the thread comes level with the bottom of the screw slot. Fit the adjuster to the pressure place and screw in until it just touches the push rod, then screw out one complete turn. Adjust the cable to give 1/16 - 1/8 free play. Put the bike in fourth and spin the back wheel with the clutch lever pulled in so you can assess and adjust any wobble. Job done.

I have two 66 650's both with perfectly good standard 6 plate clutches. I do not subscribe to the idea that these bikes were used as daily transport with clutches that did not work and the only cure is to spend a fortune on aftermarket "upgrades".

Rod
 

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I have never had a problem with a 6 plate clutch and often wonder why there are so many problems.If the parts are in reasonable state of decay,it usually works fine.
Be aware that most of these gearboxes will crunch a little and a good quick stab of the gear lever is needed.If you have drag,it will always crunch a lot.
 

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Hi Ade, I don't know what oil you are using in primary. It makes a huge difference.

I would try ATF F or ATF Dexron III. The difference between the two is how fast it grabs plates. Dexron III in my experience gives a smoother take off. If you have F in the shed, just try it.

To be clear no need to take clutch apart. May take 100 miles to fully work different oil into plates.

Here's a link I found on a quick search to give an idea of what you might try. Interesting how the oils in UK seem different from USA. Who knows the real difference??

http://www.autoparts.uk.com/comma-aq3-automatic-transmission-fluid-1l.html

I've found the thrust washer behind basket can effect drag with motor running, but be very free with motor stopped. However I don't know how much clearance might cause problems. The one I have in mind had about .017" play with feeler gauge. Free stopped, slight drag running. However when in gear at a stop light I didn't have sensation it was wanting to pull bike forward at all. The issue was clunking into gear at idle. If clutch was held 15 seconds or so it would free ok & minimal clunk.

I would give the ATF a good try. ATF will not cause wear in chain or tensioner or other parts in primary.

Also do you have a Vernier caliper or depth gauge? If so I'd be most interested in knowing what the actual lift of pressure plate is, measured at plug hole in primary cover to adjuster screw head. An assistant to hold lever while you measure is very helpful. Note: sometimes wife or husband is not best choice for assistant. I'll let you decide that...

Trans oil can make a large difference also. I recently switched from a very slippery synthetic 75-90w to old fashioned gear oil. It made the crunch into gear better. Counting seconds of clutch pull to let trans coast to a stop motor running could be 5 to 10 seconds less with old type oil. I don't know UK oils so can't advise what is best.

Don
 

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Discussion Starter #12
Hi All
Snow stopped play

Dismantled the clutch and found the problem
Put together by a real bad mechanic (Me)
On removal I found that the tab washer between he shouldered washer and shouldered nut was all out of shape
It must have slipped off the shoulder of the bolt while assembling, locking up but on the side of the washer and not the faces.
Clutch movement must have just crushed the washer more leaving a gap

On reassembling I found that it was hard to keep the tab washer from falling off the shouldered nut
So big lump of grease to stop it moving and tightened it up.
Followed all your advise on assemble

I can now select 1st without the grind.
Still needs a road test after the snow has melted

Now to find out where my chain is rubbing, I think the modern heavy duty ones are too wide for this old dear.

Thanks for all your help

Ade
 

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Check the engine mounting bolts at the rear.The one at the top where the chain runs is supposed to be,nut on the outside.Many people bolt these plates on with nuts inside for appearance.The chain will hit if the nut is inside.
 
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