Reviving Old STI And Trigger Shifters

I've read a lot of things online saying that Shimano STI shifters have a "shelf life". Once the factory grease hardens up, the shifters stop working, and supposedly can't easily be fixed. I'm here to prove otherwise. If the little pieces inside the shifter mechanism aren't broken, then there's no reason to replace old shifters. All you need to do is flood them with some kind of penetrating lubricant. Here's an old 8 speed 105 shifter that isn't working:

Now take your spray can and inject lots of oil into the shifter mechanism:

Be creative. Wherever you see an opening, just spray lots of oil (here's a really good spot):

Work the shift lever until you can feel it catching the pawls inside. This usually takes about 15 minutes to free up the shifter. If you've been playing with it for a while and the levers still won't click, then set it down and give the penetrating oil time to do its thing. Also, for whatever reason, loosening the center allen bolt on top of the shifter a little bit seems to make these things work more easily. Don't play with the allen bolt unless the oil definitely isn't working, and don't even think about removing it completely. If the shifter starts working again, then tighten the allen bolt down so the shifter won't come apart later on.

This trick also works on mountain bike shifters. Here I have some old 7 speed Alivio trigger shifters that have seen better days. I find it's easiest to carefully remove one of the plastic covers over the shifter in order to spray the ratcheting mechanism directly. Here I unscrewed the 10mm bolt on the bottom:

Now the shifter should stay intact, but be really gentle when removing that cover:

You can now see the little pawls and springs that need to be flushed with oil. Alternately you can remove the top cover by unscrewing a few small philips screws:

That's pretty dirty inside, no wonder it wasn't working. If you do it this way just make sure you get the plastic gear indicator to line up properly before you put it back together.

In case you're wondering, I used Liquid Wrench brand chain lube on these shifters, but I've even used WD-40 in the past. I also like to flood them with motor oil after flushing them out with spray lube, just to keep them from gumming up again. So far I haven't failed to revive any trigger or STI shifters this way (knock on wood). Hope this helps!