Triumph T120 1968 - clutch keeps coming out of adjustment

Hi, I've found myself with a 1968 Triumph T120 R. Being a Norton guy I'm surprised to find myself quite enjoying the bike. The bike needed some re-commissioning to get it back to working order but I have no plans to super-restore it. I quite like the original patina of the machine.

However, I do have a reoccurring issue that I cant quite fix. The clutch keeps coming out of adjustment. The symptoms are the kick start not engaging with the engine. So I'll pop the cap off the primary case cover, release the nut holding the clutch actuation rod and give it half a turn anti clockwise. Nip up the nut and hey presto the kickstart engages and the bike rides well. But I only need to ride 20 miles to work in the morning, then when I go to start the bike in the evening low and behold the clutch is slipping again. So I've had to bump start the bike in the car park which is super embarrassing.

Does anybody have any thoughts on what might be causing this?

Is the symptom that the clutch slips when you try to kick it over? Meaning, it's as if you've disengaged the clutch with the lever? If that's true, I would have the primary cover off to check the adjustment of the pressure plate springs. The stud tops should be somewhere in the threaded portion of the button head from the bottom of the slot to the top of the nut, and the plate should have minimum runout with the clutch disengaged. While you're in there it's probably a good idea to check the free length of the springs themselves

That’s quite a strange one IMO…

Basically, that adjustment can only be taken up if something is allowing it to be taken up, ie the clutch pressure plate is being allowed to move inboard somehow.

The only things I can think of that would allow that are A) clutch plates wearing and B) the thrust washer behind the clutch basket wearing. But neither of these things should wear significantly enough to allow such movement in only 20 miles. And both only act in a wearing motion when the clutch is depressed.

Also, if the clutch slips so badly that the kickstart can’t turn the engine over, it should also slip like mad in use. Get it into 3rd or 4th on a slight uphill gradient and give it some beans, that’ll tell you if the clutch is slipping.

I‘m wondering if it’s something else entirely and the clutch adjuster is a red herring?

If it persists you’re gonna have to go inside the primary cover for a look see. It’s a very quick / easy job. Irrespective of the root cause of this issue, as mentioned above, it’s essential to adjust the clutch pressure plate so it turns as true as possible, if it doesn’t, you’ll get slip AND drag. The only way to check this is to have the cover off and watch the plate turn as you turn the engine over with the clutch depressed.

This doesn’t sound right.

“Kickstart not engaging” is very different from a slipping clutch. Is the clutch slipping? Do you know what a slipping clutch feels like?

IF it were the ' drilled through ' case , common primary & engine oil , Friction Modified oil would cause clutch trouble .
Retro Mod , so maybe ? .

PUSHROD ! . Yer wanna check its the RIGHT LENGTH . often a bearing Ball ( Ball bearing ball ! ) is fitted in the clutch cover fandangle .
This is so idiots HOLDING THE CLTCH IN dont overheat & soften the pushrod end , so much .

Like this . https://www.feked.com/triumph-clutc...-with-ball-pre-unit-350-500-650cc-models.html



Were aftermarket ' face ' bearings , too .

If the end off the pushrods BLUE & Deformed , its overheated & deformed - and likely TO SHORT .

Only de*d shirts hold in Triumph Clutches , at traffic lights etc .

We wont mention pointsmen & four lanes off easter traffic . Woulda made a good video .
No one got run over , and all there brakes worked . He thought I had it in gear . As I had earlier .

A T F is usual Primary Oil for a non vented unit Triumph Primary . You want it all clean in there .

Addapting to the adjustable tensioner , its setting determines gear change , to a degree .

COLD , you kick it through , lever IN , to unstick it . Unusal for a person to get first without a C R U N C H .
So the whole mechanism wants looking at carefully , if your in there . Faultless & a low idle . they can ' Schnick ' In . !

Stupid cables & Brass on alloy or steel on steel , at the bar , can cause GRIEF . As can a worn lever pivot etc .

SLIPPING , you DONT slide the clutch . You LET IT IN .

If your Slipping It , the G O O K from this can cause your irritations . S'not a diaphram semi metalic clutch , like a commando .

There was a video of two half with honda boys on Triumphs on the California coast , crashing gears and abusing them generally .
SO the first trick is to set it up with NO DRAG , and adequate push rod travel . And if its running properly it should pull the ton . In third .

You check these for wear , if youve got it apart .

Ridges & burrs , and on the clutch ears . Hammer & file !!!
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Try whacking the three adjustment caps on the springs right in . coil bound , carefully check the lever .

This relates to lever travel - They should about not restrict the lever , correct bite . ( The cable shouldnt ' bottom out '
before the lever gets to the bar .

GENERALLY its the nasty little cam / lever , at the other ( cable ) end thats a snot . Checking over THAT thoroughly
should get you in buisness .


Check balls & burrs etc . Galling .

The nut on the mainshaft on the kick starter side is coming loose.