Britbike forum Forums British motorcycles in general British motorcycles in general Grease and the Clutch Rollers?

Putting a 67 T120 back together after 2nd try indexing the gearbox/shifter. Fitting the 20 rollers into the basket and hub, using my sticky grease and a stick magnet. I've always enjoyed this little ritual. Then I remembered: didn't John H say we're not supposed to use grease? Then I wondered why not? All done now, but this sort of mechanical esoterica always interests me.

i use grease. its going to get coated in oil anyway after two minutes and the grease helps you not put em in sideways

why would you not lubricate the bearing that the basket spins on whenever you pull in the clutch lever?

I have always used grease - you can also use assembly lube too

Whatever you put on the rollers will go into the primary oil. On early separate primary/motor oil you will be putting some grease on your clutch plates. On later breathe through primary engines the grease will also be going through the motor. Granted, thinned down. Wheel grease has fibers in it which you do not want in the shell bearings.

i cover my clutch plates with white lithium grease anyway, dave. and im not careful about wiping it off.


i use disc brake caliper grease on this stuff, as opposed to the hairy wheel bearing formulations


white grease on the clutch pushrod is still there after 200 milez or so

Seems like a non issue to me, but was curious about the rationale for not using it. Never thought about the fibered wheel bearing grease, I like that stuff, too, but only in the wheels.

[quote]Then I remembered: didn't John H say we're not supposed to use grease?/quote]

While I see no reason to use grease when offering the clutch rollers to hold them in place, or for later lubrication, I cannot remember saying don't use grease. The tension from the primary chain holds rollers in place as the next one is offered. Offer a roller. Then slide it to the back where the chain tension will hold it in place. Then do the same as you offer the next roller until all 20 are in place. Some lubrication from the same oil you will later use in the primary is certainly appropriate.

I guess I have just misremembered.........not the first time. Thinking of something else probably, thanks John.

johns dry method
probably works if you have done this enough times that you can do it with your eyes closed .
but if youre re-building a clutch in place , only on the odd occasion , like when you absolutely have to
... holding the basket and chain in on hand ,
placing one roller at a time with your second hand ... and hoping it stays in place while Wrangling up the next roller .
is like that circus act juggling plates on the Ed Sullivan show ...( this childhood memory still haunts me )
until enough rollers are in place
one dropped roller spoils the party
gravity isn't your friend here ... but a little grease is .

When I ran a standard clutch setup I would place the clutch hub flat, basket on then put the rollers in from there and push the Cush drive on after. It was sufficient for keeping it all together. But your relying on blind faith that the hub goes on the shaft squarely and not off set by the key, with the basket in place the visual check is restricted.

I'm old and my hands shake. And I can't see worth a damn, trying to hit that key with that stuff assembled seemed like a long shot.

"He's old, and his skin is cold"


Sorry Winn, I couldn't resist !!

Every time I try to assemble the whole thing and slide it on the shaft I hear that faint tink in the bottom of the case which tells me that one roller has just freed itself. Probably why I've taken apart so many which only had 19 rollers in there.
I'd rather do it as JH describes, the only difficult one is the last roller.

To be honest it’s one of the reasons I stopped fitting keys. Although last time I had my clutch apart I did fit an original key and it did go on well and true.

wait

allan, you dont use a key on the main shaft?

at all?

I didn’t do for many years. The taper on the main shaft is what’s doing the work, the key does very little.

If you were running a spline then, ok the spline would wear if the nut wasn’t tight but it would still propel motion. If the nut isn’t tight on a taper then that key is just going to sheer. It’s doing very little in respect for keeping the mainshaft turning.

tridentman is nodding his head. i can feel it

ive sheared keys when the nut wasnt tight. what i do is paint the end of the key bright yellow and then run a tracer line down to the end of the shaft. when i put the clutch on i can see the end of the key using a little flashlight

i do the same on camshaft pinion keys

Nod nod— you are correct,Kevin!
The nut obviously needs to be tight but the torque is transmitted by the taper.
Arguably you reduce the torque transmitting capabilities by having the key way there.
You should only use a key way if you want to fix the two parts together in a particular place.
A good example is to fix the timing in a flywheel magneto.
But for a clutch of this design— no!
Leave out the key but lap the clutch center and the main shaft together using fine valve grinding paste.
Make sure the grinding paste is thoroughly cleaned off afterwards.
Make sure that the clutch nut is really tight and away you go.
Just my two cents worth of course.

The only way the hub could be offset by the key is if the key is damaged and not sitting completely in the slot. The slot is always deep enough so the key does not hit the top of the slot.

David, How about showing these Guys that clutch you are building.............. Just for fun!! ;~))

Dave— all I am saying is that if the key way we’re not there then there would be extra taper area and therefore the capacity to transmit more torque.

I think if you investigate this all the key does is make it easier to tighten the nut and pull the taper together without it spinning. It is an awkward taper to tighten.

I agree with Tman.

While many will argue the point, I was taught in school never to lap a taper. Also Johnson Motors, in a booklet on how to prepare a T140 for racing, they also recommended not to lap the taper.

If both the gearboxmainshaft and the clutch center are new then I would trial fit and if snug then I would not lap the surfaces.
However at least one of those components is probably 50 or more years old and has probably suffered at the hands of previous “experts”. For example the main shaft key way is often less than pristine with people putting in and taking out keys.
So I always do a light lapping- to get a good uniform dark grey over the whole taper on both components.
Just my way of doing things.

powdered chalk was an old taper trick if it was suspect. I have used this.

Dave

The fit of the clutch hub on the main shaft of my race Triumph is not the best. Tighten to 60 ft lbs and then back off the nut, the hub comes off easily with the slightest tightening of the puller..The hub is genuine NOS Triumph....it has never caused a problem for land speed racing..