Triumphrat

Odysseus · 10-13-2005

In reply to the (last year's) question about problems on 2001 bikes, recently revived by Boozefighter, one or two people mentioned "clutch chatter". Mine is 2001 and suffers precisely that problem. Does anyone know exactly what causes the problem, and what the fix is? I asked my dealer about a recall, and he couldn't find any record of one, at least for my frame number, and I'd appreciate any help in pointing him in the right direction.

Bryan · 10-13-2005

What type of oil are you using? :???:

donco · 10-13-2005

Bryan is right on with this one. It's known in the physics world as "stick-slip instability", which is caused by differing static & dynamic friction coeficients in the clutch plates. There is a higher friction coeficient when the plates are firm against each other moving in unison, than there is when the clutch lever is squeezed and they start to separate and slide against each other, which induces a harmonic resonnance in the clutch pack, a.k.a. chatter. The oil must be properly formulated to bring the two friction coeficients closer together. The friction modifier(s) will break down with age, usage, and heat. Either it's time for an oil change or perhaps switch brands, make sure it's rated for motorcycle "wet clutch" friction surfaces. If that doesn't solve it, and the dealer can't resolve it, you might try using an automotive limited-slip differential fluid conditioner as an experiment, it's sold in 5 or 6 oz. containers at most automotive parts places and you pour it in directly with the oil, it's fully compatible with all oils. Give it a chance to work in and if it changes for the worse, do another oil change and don't use the LSD additive.

Mine was getting grabby a few weeks ago right after an oil change. I switched to a full synthetic 10W40 motorcycle oil, not knowing what was in it before or when it was last changed, and as best as I can figure, the friction modifier additives in the new oil were a bit too strong. It has since smoothed out and is running perfectly.

jojje1963 · 10-13-2005

Yes, the oil plays a roll. Fully synth motorcycle oil will make it better but if you have more power than stock the clutch might slip. Ester type oil like Motul semisynth might stop the slipping but you might get more chatter.

BUT, there was a design error on the 2001 clutch center. The rear trust surface was too narrow so the aluminum center got worn with time and then it started to chatter, I got mine replaced for free and all was well.
You can see the old and new design in this pic
http://www.stabbarps-auto.com/images/clutchchatter.JPG

[ This message was edited by: jojje1963 on 2005-10-13 19:48 ]

Odysseus · 10-14-2005

Thanks to one and all. That should give me enough to get started. The chatter only appears when the engine is hot, both in cold and hot weather, and only going down the gears, especially in first, but occasionally in second too. The oil I use at the moment is a Mobil synthetic (I can't remember the grade) supplied by the Triumph dealer, and the chatter existed before the oil change and after, which makes me wonder if the clutch defect mentioned by jojje might be the root of the problem. I can induce it just by riding forward at just five or six mph in first and then pulling in the clutch lever as I brake, and no amount of clutch cable adjustment will eliminate it completely.

[ This message was edited by: Odysseus on 2005-10-14 03:25 ]

grebmrof · 10-14-2005

Correct information is being provided. My '01 has a build date of 01/01 and this was one of two problems that I had (the other was oil in the airbox, a lot of oil). Both problems were addressed by the dealer, but the clutch issue took three visits, each time the dealer installing one further step in the fix. I thought one of the fixes was a longer actuating arm, but perhaps this was a false attempt to address the problem. In any case, I would guess the clutch part jojje sent the picture of, is at the heart of the issue.

Hope you don't have an issue with getting this fixed so many years after the problem, in any case, the dealer should be able to find a technical bulletin on this problem - this is well known at the Triumph factory - unless their memories are fading.

Good luck, keep after it, no amount of oil changes or changes in grades of oil will address this.
Tom

boozefighter · 10-14-2005

Once the clutch is ready for replacement you might want to think about the heavy duty clutch available from afermarket sources. Joe :-D

Odysseus · 10-15-2005

Jojje and Tom have confirmed what I suspected, and I think it's the route to follow for the moment. I'll be printing off Jojje's photo to take along to the dealer, so that he knows what I'm talking about. I'll keep you posted on the outcome. Thanks to all once again.