I searched the forums and reviewed the Shimano tech sheets, but can't find an answer to this.
I have a Shimano Sl-8S20 Revoshift for a shimano 8speed IGH. I'm installing the old system on a new frame, and decided while I was at it, to replace the cable.
Following the directions on the tech sheet, I unscrewed the screw and removed the top cover to access the cable housing and the stopped end. When I removed the screw and the cover, two little springs popped out. These tiny springs (1/8" dia) each have a "leg"on them, One leg is longer than the other, and one spring is longer than the other. My hunch is that they nest together with the "legs" about 120 degrees apart. However, I cannot for the life of me figure out WHERE they go.
They're not shown or mentioned on either the revo-shift specifictech sheet, or anywhere on the overall IGH tech sheet.
This is not the spring which provides the resistance for the adjustment barrel.

I can re-assemble the unit without them, and it seems to otherwise work...
I'm wondering if it's safe to leave them in the mystery left over parts drawer, or if they're vitally important in some way I don't understand.

https://hubstripping.wordpress.com/nexus-inter-8-shimano

Hello welcome to the forums. I would not reassemble without them, there are in there for a reason. not having used this shifter I am not sure what you are talking about. can you post some pics? I don't think I ever heard of shifter that required it to be dissasmebled to install a cable.

I did check the hubstripping site before posting, but all I found was the same tech sheet that shimano provides. I'm sure the guys at my LBS (Harris Cyclery) will be able to help, I just can't make it out there next weekend, and need to get my bike (principal mode of transportation) up and running.

I wouldn't really call it disassembly, you just have to remove a cover to get at the captured end of the shifter cable. I will see if I can get pictures if you think this will help. I just don't understand how they can be critical if they're not in the tech diagrams from Shimano.

Seven years later, and I have this exact same problem. How did you solve it in the end?

this is the MOST detailed exploded view i could find on that twist shifter...
https://si.shimano.com/pdfs/ev/EV-SL-8S20-A-3279.pdf

the springs are not shown... i'd think they may be part of a pawl/detent system inside the shift mech. itself, and Shimano considers that part un-serviceable?... frankly, the one i've got here(7sp. model) is not quite the same, but feels like a normal "flexing finger of the housing" type detent...the DIFFERENCE between your 8 sp, and my 7 sp, appears to mostly be the INDICATOR, not the shifter itself... is it now loose, or not precisely located when you shift?

if it works ok on the bench, go test ride, and be aware of ANY unusual operation... or, if it really bugs you, or doesn't work correctly, a new one is about 25 bucks, on Ebay...

but.... if you're like me.... you'll still want to know WHERE they fell out of, right?

look in the twister detent area... The COVER should not be a factor in their staying put, so.... they came loose on their own... i've changed a couple cables in that style twist shifter, and no small springs fell out.... so far....

For what it's worth, I can't for the life of me figure out how to snap the thing back together. It's very easy to pull open the the shift mechanism itself, and near impossible to put it back. This time, the lesson was only $25 and two hours. That's cheap learnings compared to some

the COVER? yah...they're a bit of a pain... the tab is the key, and then, you must insure that the little guide that the cable bends around is all the way seated... it will prevent the screw area from fitting tightly... and THEN, you must make sure the CABLE is correctly seated into that guide to fit the cover down snug... note the thin retainer on the cover that holds the cable in the curved guide... THEN, the screw boss needs to fit EXACTLY onto the threaded hole in the shifter body... snap!

rather annoying , aren't they? try doing carbs on old chainsaws sometime... i termed them "open heart surgery"... and had a huge magifying glass with the bright lights on my bench for those buggers... some had tiny valve/check balls, and springs of different rates holding them in valve ports... and then, there are the flexible, adjustable, fuel pressure compensator arms that MUST be properly set during assembly............. and held in place while you start and snug down the retaining screw that traps the pivot pin on one side only.... and then, those wonderful, leaky old welsh plugs that need dimpled into place after you clean the passages under them..... the new formula gasoline eats the sealant off of them, and then the saw/weed eater/ etc., refuses to run correctly... rebuild times were in the one hour range, and a new carb was between 15 and 40 bucks, so........ yah, we REPLACED the carbs.... if they were available! The customers always complained when we didn't "just rebuild" their carbs.... that shop's repair labor rate was $75 an hour, then... higher now!......... sigh...

oh, and i'm an old Bass guitar player, so my finger tips are calloused like leather gloves........

Brand new Trek T900 w/Grip Shifters. The right-hand unit split apart in the 2nd week and the twist grip will not lock into the stationary part anymore. It shifts fine, sort of, if I remember to apply inward pressure as I am rotating the grip. Solution:triggers. Recently bought a ~20y.o. Burley Samba Tandem w/Grip Shifters. Really, really leery about them even though they look and feel solid and are obviously way better constructed than newer ones. They are there for now but I am on the lookout for some triggers to replace them with, my knee jerk reaction to anything head scratching concerning a Grip Shifter(s) is replace with triggers ASAP!

If the Shimano Sl-8S20 Revoshift is made like their other Revoshift twisty grip shifters it isn't really user serviceable. Everything snaps together with plastic tabs, the cheapest possible form of assembly and it's designed to be a one-time only process. When components like that fail they're usually replaced rather than serviced.

Without great care to avoid marring the snap-in tabs it'll never reassemble securely. Most video tutorials I've seen show the DIY tech using a screwdriver tip or something similarly hard, marring the plastic tabs in the process. You'll need a tool softer than the plastic. Filing down a wooden popsicle stick or tip of an artist's small wooden handle paint brush should work.

However it should be possible to remove an old cable and thread in a new cable without disassembly. To experiment I disassembled my old broken Revoshift, which confirmed my hunch that it's not designed to be repaired or serviced, only replaced. But I could see it was possible to replace the cable without disassembling the Revoshift. It's a bit tricky to aligned the bits inside to thread it through, but easier than trying to disassemble/reassemble the thing.

After my first experience I bought a complete replacement set of Revoshift 7-speed shifters with cables pre-installed from Nashbar for less than $10, just in case I ever need it.

It's not entirely helpful to tell me I don't have to take apart the shifter, when I've already taken apart the shifter. Life doesn't have save points, I can't go back in time