Bicycle Mechanics - Cleaning, lubing DA shifter innards

This question is addressed to anyone with thoughts on it, but particularly Pokey and D*Alex who tend to be conservative about flooding things with degreaser.

My right (rear) DA STI shifter is "sticking" a bit, ie, when I press the small lever to shift to a smaller cog, the large lever moves, too, so nothing happens. Pushing the large lever shifts to a bigger cog, no problem. If I hold the large lever so it doesn't move, the small lever will shift properly. Der is working fine. I stopped by my LBS yesterday to let my favorite wrench take a look since they had to send another DA lever back under warranty a year or so ago for similar symptoms. The wrench said this was different since last time there was actually a problem with the ratchet mechanism. He said what I am experiencing is common with the STI levers when they get a little dirty inside. He suggested squirting degreaser in, let it sit, rinse thoroughly, dry thoroughly then squirt in lube such as Tri Flow.

I am a little hesitant to do this without getting some additional opinions. It seems some of you have mentioned that flooding things blindly with degreaser can take out ALL lube, including some that might not be adequately replaced by squirting some in. Does this procedure sound OK to most of you?
Thanks,
Raymond

I wouldn't touch this one with a 10' pole..........

I have some real old ones that have never been hosed out.The fact that the big lever moves too suggests it's more than just dirt.Have you checked the little screw on the upper backside of the big lever? Have you checked cable routing and the small loop of casing at the deralier, for anything possibly hanging up, or a frayed cable?...If all else fails,you got nothing to loose by hosing them out.Relube with a spray like triflo.

If Pokey's suggestions don't cure the problem, and you wind up cleaning them, here's my $0.02. You don't need degreaser per se. I did my Ultegra shifters a couple of months ago.

I was replacing cables at the same time, and didn't want to make a mess all over everything, (including tires, rims, etc.) so I removed the levers, and pulled off the rubber hoods. I cleaned them by spraying lots and lots of WD-40 into the ratchet mechanism, while working both levers to try and thoroughly work it in. After letting them dry overnight, I dripped Tri-flow into the ratchet mechanism, and rubbed grease on cable connector pivots, etc., that I could get to. As you know, WD-40 isn't much of a lube... I think it has a little silicone in it that remains after the carrier evaporates, but it's gotta be better than something that strips all lube. In retrospect, removing the levers wasn't really necessary if I'd maybe just laid the bike down and put a pie tin or something under the lever during cleaning... it made for a lot of extra nuisance work (positioning levers, retaping bars).

I suppose you could could immerse them in something like diesel, which acts as a solvent, but is also oily, so you'd be guaranteed some degree of lubrication. But it's probably not necessary, and there's the drawback that it'd probably never dry.

I've used the bike probably 5 times a week since, albeit mostly indoors on a trainer. So far, no problems. Good luck, whatever you do!

The installation instructions for the DA levers also have instructions for partial disassembly for cleaning.