I am 10 years into my Dura Ace shift levers, which have performed wonderfully for the duration. Recently during a ride, I noticed a rattle which was significant and steady while riding on anything other than the smoothest of surfaces. I put up with it for a few weeks, but eventually it was driving me nuts, so I decided to dig in cautiously. These combination shift/brake levers have numerous small parts with an equal number of opportunities to render the thing incapacitated if mishandled. I haven’t dug into these beyond removing a few surface screws and access panels to add lube and replace cables and I didn’t want to start today.
Listen, I’ve read all of the blog posts of people with similar problems, so I will spare you the trouble of wading through 3 more pages of back-story. After carefully poking and prodding at the various cams and joints and moveable parts, I noticed the silver arm that is clipped in behind the front part of the lever on one side was a little looser than the non-rattling side. After closer inspection, I found there was a small grommet that was used to secure the brake lever control arm to the lever itself, and it looked as if it was about to fall off completely!
Here’s what that looked like:
Keep in mind, nothing in the shift lever itself needed to be unscrewed, removed or loosened… this is all accessible directly on the back of the lever. The only requirement here is that you push and hold the shift-lever all the way over so that it is out of the way so that you can access the grommet that holds the brake lever control arm.
My fingers were too fat to get into this small area, so I carefully used the blunt tip of a screwdriver to press this rubber/metal grommet (#4 above) back into the clip made to receive it. This secured the thin silver brake arm to the control lever and solved the rattle issue!
Maybe this will help you too. If not, I feel your pain… there are many small parts in there that could have been causing this. Good luck!