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Looking for some advice and support here guys. I did put this in the bikes n bits wanted section but got no response. Perhaps more people might see it here. I have a 500 - but my problem applies just the same to the 350.
Had a spinning clutch stud. Have managed to remove it, and have purchased a new stud from NLM. Have also bought a M7x1.0 tap. My question is aimed at anyone who has actually replaced one of these studs themselves. It looks like when I tap the hole and fit the stud, only one thread will be in contact, and the stud will protrude out the back of the clutch housing. Do you peen the end of the stud after screwing it in? If so, how did you do it? Did you weld it in place? Did you have to grind back the stud so it is flush with the back of the clutch housing?
Any advice gratefully received

Nick

Sorry for not posting this sooner.

I replaced some a while back- I ground it flat, welded it then ground it again.

Remember when you put it all back together that you don't have to do up the slotted nuts tight, as the springs stop them coming loose. I turn mine 'til they stop then wind them back 1/4 turn. If the clutch slips it's because the spring cups have stretched and are contacting the base of the inner basket- take them out and tap them on the pointy end with a hammer to squash them slightly, and swap the 'thin' friction plate for a standard 'thick' one.

Hope this helps! Andy

I have the spinning clutch stud syndrome. How did you get it out?

Not a lot you can really do; try & find a way to stop it spinning long enough to drill into the stud...

Does the clutch have to come apart now, or are you just doing it 'cos you know the stud has come loose?

No. Clutch is working fine at the moment but just worried about the consequence of the stud becoming completely detached while I'm riding it .........

Morini Rich wrote:I have the spinning clutch stud syndrome. How did you get it out?

First some doses of penetrating oil.

Use a punch to mark the centre of the stud. Hold the nut in some pliers or grips and drill a hole down the centre of the stud (try 3.5mm).

If you're lucky, the torque and heat generated by drilling will unscrew the stud from the nut. You could heat the nut and stud up first to give it an extra chance.

If it didn't unscrew, then work up through the drill sizes. If you're right on centre, you can drill the stud out leaving the nut intact, but they're not too costly if you miss.

I sometimes have to dismantle equipment built with very small, machine tightened, torx screws. The heads often strip, but they come out just fine with a left hand drill-bit.

Thanks. I'll give it a try one wet weekend! (Shouldn't have to wait too long for that)

The way I got the spinning stud out is as follows.
First, I tried to make a slot in the end of the stud to try to hold it steady with a screwdriver

That did not work - could not get enough force on it.

So next I decided to drill a hole at an angle in the nut, and to insert a bar to stop it spinning while I drilled out the centre of the stud. Use the new stud and nut you have already purchased to plan how far to drill, and at what angle.
Centre punch for hole

Drilled out the hole and started to drill out the stud

Put a bar in the hole, steady it against the brake lever, and then drill out the centre of the stud.

It was not easy - I had to be very careful it didn't all slip out of position. If you take your time - it is possible. You will reach a point where the nut will unscrew. Again, use the new stud to plan how far to drill down. I used gradually larger drills - and managed to drill my initial hole off-centre which didn't help, but it came right in the end.
This will enable you to remove the nut so you can then dismantle the clutch. The stud will still be in the clutch backplate. I carefully chipped away at the peened over end of the stud with a small hard tool. Sorry - no photos of that job.
The next stage is to get hold of a M7 tap - I got one for £6 from Cromwell Tools. Use a pillar drill to make sure you tap the hole square. I found no need to pre-drill a pilot hole - the hole was near enough the correct size (6mm).
Next screw in the new stud, and then weld it in place - there is a large countersink on the rear that you can fill with weld.

Sorry about that photo - not too clear. To the left of the weld you can just make out where the wheel material started to be eaten away by the weld process. Oops! I think the wheel was cast rather than machined from scratch. The consequence of this? - welding onto cast material is not as strong. But hopefully this will be ok - it is not as if we are applying a constant radial torque to the stud in operation. The stud protruded about 1.5mm through the back of the plate, and I covered it with weld. Through the whole process, consider the fact that this spins at high velocity and you do not want it out of balance. Consider how much material (qty and weight) you are taking away and adding.
Next job is to grind the weld flat - CAREFULLY!
You should then be in a position to rebuild the clutch.

Hope this is useful.

Nick

Nice job!