Friction/Index Downtube Shifter Problem
 

Have a Shimano 600 SIS/Index 7 speed downtube shifter on a late 80s Cannondale road bike with a Sante rear derailleur RD-5000. The lever stays in the SIS position fine, but when I switch to friction and move the lever at all, it goes back to SIS. Any thoughts on how to fix this. I replaced the cable and the shifter screw is tight. Any thoughts appreciated.

Is there a washer missing, perhaps? I don’t know this shifter, but you may be able to find something useful in Shimano tech docs, and then compare the parts you have vs a diagram.

https://si.shimano.com/#/en/search/K...=600&name_web=

Does the shifter making a ‘click’ sound when you rotate the D-ring between index-friction?The sound comes from the detent for each mode.

Had a hunch, maybe the lever bolt was too tight. Seems I was right. Loosened the bolt and all seems to be well, back and forth between SIS and friction seems to be working. Sorry for the bother. Maybe this simple solution can make somebody else's day! Cheers

It does make a click sound now, when I switch to friction, which didn't happen before I loosened the bolt. I,m still wondering though, if some kind of washer might be missing, but I haven't seen any indication that this is the case.

I don’t own 600 shifters but the Shimano 6,7 & 8spd DT shifters that I have don’t use a washer.

Glad you’re up and going!

Good catch on that these two function late 80's early 90's light action Shimmano shifters can be a bit touchy if any of the adjustments are off several of the bikes I have had with them required light tuning about every couple hundred miles.

Thanks. I think I'm good. I just looked up the schematic https://si.shimano.com/pdfs/ev/EV-SL...6401-0845B.pdf and there's pretty much only 3 functional parts to the lever, and no washers apparently.

Thanks for pointing that out, seems exactly what I've just encountered. Model number of the lever is SL-6400, BTW

Also I should have pointed earlier out but you need to readjust the cable tension screw adjuster several tuns tighter when you switch from indexed to friction.

Thanks. Sounds like a good tip.