Hi!

I'm having some problems with my 3-speed front shifter. There are basically two problems.

One, when I shift from the smallest to the middle chain-ring. I sometimes get a kind of "micro shift" the derailleur moves a bit to much, and the chain starts rubbing against the inside of the cage. This can be remedied by pushing the down-shift lever so the cage moves down a couple of millimeters.

Two, when I shift from the largest chain-ring the chain jumps directly to the smallest chain-ring.

The thing is both of these problems are rather random. I can adjust the derailleur on the stand (or hanging from the ceiling in my case) and everything works great. But sooner or later one of the above things happen, and i have to readjust the derailleur again.

I'm beginning to suspect there is something shifty going on in the front shifter.
So my question is, does anyone know how to open one of these shifters?

I bought my son a used MTB last year with these same shifters and the front wasn't functional when we got it. I took the shifter apart (pull the screw, loosen the shifter wire and it can be taken apart pretty easily) and used WD-40 and needle-nose pliers to get all of the cams and levers moving smoothly (I had to work a couple of parts numerous times before they were really moving freely enough to shift properly). Worked great every since.

+1

Take the derailleur apart and make sure everything is smooth and sexy.

Thanks for the advice. Gonna try to take it apart and clean it up.

I would experiment with tweaking/cleaning them, but I wouldn't put too much hope in them because those early Shimano shifters with the up and down buttons on the same side are unreliable parts -- in my experience.