Bonneville America Forums Forums Technical Forums General Tech Clutch slipping

Recently I've noticed when seriously twisting the throttle (not necessarily downshifting), it appears the clutch is slipping slightly as the bike accelerates. There is plenty of play at the clutch lever. Is this a clutch spring issue or sign of something worse? Never noticed that happening before the 904. I may have noticed it only rarely the last couple of years. It is happening a lot more lately.

The only oil used in the bike has been Triumph recommended oil bought from my Triumph dealer. Appreciate any input.

You probably need to fit the heavier clutch springs.

I remember a few of the 904s being fitted with the heavier Barnett green springs for this very reason; all the same, what mileage is on the current clutch? You might be a candidate for some new friction plates.

I have Barnett red springs and my clutch slips now... actually it's been slipping for over a year... I have new plates coming. The red springs are crazy stiff, ask anyone that has pulled my clutch lever.

I first noticed the slipping a year or two ago. I thought the clutch cable might have been too tight causing the problem. It didn't keep happening so I thought that was it. But now, it's happening every time I hit the throttle hard - especially riding 2 up.

Is replacing the plates an expensive repair? It's weird that it happens hitting the gas hard even staying in the same gear.

I had the dealer replace the clutch plates and springs (Triumph heavy duty). The bike had 22,000 miles on it with original clutch plates and springs. The extra torque of the 904 is a little tougher on the clutch. Runs great now and I like the slightly stiffer spring feel.

It cost a little over $300. including tax and labor but they also did a couple of dyno runs and we decided to lean the needles one notch and change the mains from 130 to 128. My mileage had dropped since making changes a couple of months ago. The Hp only dropped about 1.5 Hp and the air/fuel mixture is great, just starts leaning a hair above 7K (still below 14). I don't spend that much time up there.

I just did the very thing you are in for now. I did it with out any of the specialty tools ( it would have probably been easier to but it only took about 2 hours to do the whole job). If its been slipping for a year you will need friction plates. If you would have caught it earlier. you could have gotten away with just springs. I got the barnett clutch and spring kit for $165. With the gasket and new oil I was near $200. The job is not that hard. It was actually pretty fun, and interesting. Word to the wise There is a beveled ring inside the clutch basket make sure you put it back the way it comes out. Attention to detail is the most important thing on such a job. I got a copy of the manual on hard drive I can e-mail it to ya if you need it.

If you have an overhead hoist or a motor puller, you can rig your bike to securely lean over hard to its right side, almost to to pegs, you can minimize oil loss to about half a cup and I found it actually more comfortable (body wise) to get at the clutch basket with the bike leaned over. The beveled ring that Chad is referring to is also called the wavy washer. Locate that as soon as the cover is removed and on reassembly, place it back on the starter shaft with a dab of grease. I also bought some inexpensive 3 inch long 6mm zinc chromate bolts (4) and hacksawed the heads off to hold the gasket in place and slide the case back on, after you get your case OEM bolts started, spin them out with your fingers, save them for if you ever have to remove the alternator case. Like Chad said, you don't really need the special clutch tool, but if you have access to one, by all means, use it. Just assume you will need a new gasket, you can put a light coat of your favorite gasket goop on the motor side and I put a light coat of anti seize on the case side to increase my chances of being able to reuse the gasket should the case have to come back off unplanned. BTW, if you you go with the H.D. Barnett clutch springs, your lever pull will be noticeably heavier, really a no-brainer job, if you have the book, "You Can Do IT"

don't know where abouts in FL you are, but moe, over in cape canaveral area, just did his clutch and has all the tools and expertise to talk ya through it.

Thanks for all the input, but I had the dealer replace plates and springs and got a few other things checked as well. Clutch seems to be doing fine now. Waiting to see how the carb changes affected my mileage.