Replacement St2 Clutch

From the ST2 manual :

No mention of Loctite or grease.

 

I don't think it's the frowned on bit here, more that it's impractical and nigh on impossible. To try this safely, unless you are a 10 foot mutant, you need two people for a start. And even if you do manage to achieve some attempt at loading up the nut, the indirect-ness of the restraint means that there is a lot of "winding up" before you can get a high enough effort to possibly undo the clutch nut, and as soon as you relax it all unwinds again, sometimes quite quickly. It also means that you can run out of travel for your breaker bar because you have to start with the socket and bar engaged "further round the clock" to allow for the wind-up effect.

 

You can only do it on your own with a right hand change bike. I used it to great success on Laverdas. There's a limit though and I didn't know the torque setting for the ST2 clutch was so high. It was just a general comment.

I don't see why someone helping is an issue though.

I've used a variation of this technique today with bolts torqued to 110NM. I used rubber wheel chocks placed in front or behind the tyres (depending on whether I was loosening or tightening) with the bike in gear, on the side stand, taking up the play in gearbox first by moving the bike.

It worked perfectly with absolutely no movement whatsoever.

 

"I don't see why someone helping is an issue though."

totally, all for it, if it is of Help, you've got it in one T.M. and maybe it is possible on Laverdas etc, you weren't to know that a lot of Ducatis have a cush-drive behind the clutch assy.

 

Having just had to replace the gearbox in my M900 due to the 6th gear cog losing 4 teeth, I wouldn't recommend torquing through the gearbox - the torque setting is more than the engine output!

The cost of a clutch tool is far less than the cost/bother of a knacked gearbox...

 

That's a very reasonable point. With hindsight; looking at the torque setting and the use of a cush drive it was a poor suggestion, which just highlighted my lack of Ducati specific knowledge. There's always something to learn.

Your comment about torque loadings needs clarification though.

To calculate gearbox torque load you need to multiply engine torque by gear ratio. It's a simplistic calculation but it's still representative.

Taking your bike for example (from Motorcycle Specs ZA):
Maximum torque @ 6,000 rpm = 76NM
First gear ratio = 2.466

Let's say changing up at 3,000 rpm equates to 60% of maximum torque. I think that's being pretty conservative as large capacity twins tend to have fairly flat torque curves. It's probably higher but hard to be accurate.

45.6 NM x 2.466 = 112.45 NM
At 75% of maximum torque this increases to 140.56 NM.

 

in
Just come across this one.
The clutch on my 2002 748 is way more worn than what is shown in your photos, it is noisy as fuck and rattles away like a goodun BUT, it does not slip, it disengages perfectly well, and I can pull away smoothly without juggling the lever. It's done 25k miles and I expect to get a lot more out of it. Before you spend hundreds of £ on new parts, do you "really" need to replace it, my guess is probably not but I do of course accept that I have no 1st hand knowledge of the bike so there may be reasons. All I'm saying is don't jump in too quickly.

 

Some years back my 916 (when it still had the steel basket) had almost 3mm of play between the basket and tangs, it was without a doubt the noisiest clutch I'd ever heard yet it worked perfectly, I changed it because it was too much to bear but it shows that the wear limit that Ducati give is a tad unnecessary.

As for putting 186nm through the gearbox, it might take it (do you feel lucky?) but I wouldn't advise it - my Monster gearbox broke in normal use and it's been a real PITA to fix it, it would have cost me a fortune if I was paying someone to do it.

BTW some years back I tried one of those plastic, bolt-on clutch holding tools as it would make the job much easier when you're on your own. It snapped as if it was made of chocolate, get yourself a proper clutch tool and an assistant to hold whilst you torque, especially if the engine's on the bench as mine currently is.

 

If fast acceleration is no problem you haven't got clutch slip. I would give everything a thorough clean first, check that the steel plates are all flat and make sure the small bearing in the cover plate is in good condition.

 

Thinking about it a bit more, if the vibration/noise is really excessive when pulling away but no issues once moving and having changed up a gear or two, have you considered that you might have a transmission problem - specifically with 1st gear?
Have you also properly checked you chain and sprockets? Your comment about bad vibration when pulling away but fine when accelerating at higher speeds seems to point towards a 1st gear problem?
Clutch slip usually shows up as a lot of revs but a reduction of drive to the rear wheel. A chipped or damaged tooth on 1st gear could cause the problem you describe.

 

On my Monster when the 6th gear was broken (as per the above pic) it was grating/rattling in every gear and would jam/release whilst pulling away in 1st - the 6th gear cogs are constantly rotating/meshed but only transfer drive when the selector is engaged.

Though I'd highly recommend examining/replacing the clutch before getting into the gears...