• 11-18-2012
    evandy
    Trigger shifters - servicable?
    I am currently riding an old, ancient, mongoose bike while waiting for my new good bike to be ready at the shop. As the weather has been getting colder, the shimano trigger shifters on the have been starting to slip. Everything seems to be aligned correctly in all the gears; cable line looks good, and no tendency to start to slip to another gear. However, the lever used to push it in the higher-tension direction just doesn't want to catch all the time. Seems to be worse when colder, oddly enough.

    Has anyone tried to open and service these things in the past? I'll probably take it apart and play with it once I have my new bike... but if anyone has some thoughts or tips on servicing, I'd love to hear them.

    I'll post some pictures if the servicing is successful.
  • 11-18-2012
    SkiNBike
    Sounds like the grease inside is thickening and causing the pawls inside to not catch the teeth.

    What we used to do in the shops was blast some Clean Streak followed by air inside the shifter to dislodge the old grease and then relube the shifter. You should disconnect the cable from the derailleur and shift through the gears to work the degreaser then the fresh lube through.
  • 11-18-2012
    evandy
    I'll give that a try... thanks!

    Still waiting until I have a backup bicycle, though. Well, until this one is the backup, at any rate.
  • 11-18-2012
    bing!
    you got good advice. dont open it. dunk in mineral spirits, wait a coupla days, then dry it out and lube with spray grease or thick oil
  • 11-19-2012
    zebrahum
    The ol' "spray and pray".

    We used WD-40, but any solvent should work. If you can carefully pop a cover off of that shifter without releasing any of the important parts then you can speed up the process by blasting the internals directly and picking out the consolidated grease. Just try and spray a lube in there when you're done, something light would be my preference.
  • 11-19-2012
    marpilli
    I've been able to rejuvenate two sets of older Shimano shifters by cleaning them out. Don't be afraid to remove the shifter cover. Just be careful. When you work the shifter (with the cover off) you'll probably notice the shifter pawl doesn't spring back and catch as it should. As others have mentioned the factory lubricant has become too thick or become dirty.

    I liberally sprayed WD-40 and moved the pawl with a small pick until it began 'snapping' back in place. I also used Dupont teflon multi-use spray to lubricate it (while working the shifter) before closing it back up.
  • 11-19-2012
    edubfromktown
    Be vaaawy caweful as Bugs Bunny would say.

    Depending on the shifter, if you open them up, they can blast apart like a Jack-In-the-Box. I've managed to crack open up SRAM X7 shifters just enough to get them working properly again. I recommend you read up on the type you have (if you can find info on them) before disassembling.
  • 11-19-2012
    marpilli
    :lol: Yes, it certainly can't hurt to do some research first.

    I guess I've been lucky with the cheap/old Shimanos. Oh, and never push the red button. :)
  • 11-19-2012
    zebrahum
    Quote:

    Originally Posted by edubfromktown View Post
    Be vaaawy caweful as Bugs Bunny would say.

    Depending on the shifter, if you open them up, they can blast apart like a Jack-In-the-Box. I've managed to crack open up SRAM X7 shifters just enough to get them working properly again. I recommend you read up on the type you have (if you can find info on them) before disassembling.

    Speaking in general terms: Sram are little time bombs which don't like to be opened and Shimano can have the cover removed without issue. Continuing to disassemble Shimano shifters can lead to issues, but taking the cover off is usually fine.

    Caution is your friend and when in doubt, take a picture before you take anything apart.
  • 11-19-2012
    J.B. Weld
    Quote:

    Originally Posted by SkiNBike View Post
    Sounds like the grease inside is thickening and causing the pawls inside to not catch the teeth.

    What we used to do in the shops was blast some Clean Streak followed by air inside the shifter to dislodge the old grease and then relube the shifter. You should disconnect the cable from the derailleur and shift through the gears to work the degreaser then the fresh lube through.

    A lot of products will work but Clean Streak is the best I've used, follow with a good spray lube after it dries. The only part I would disagree with is removing the cable. I leave it in and hold a little tension on it while I work through the gears.
  • 11-19-2012
    sasquatch rides a SS
    I do also find it helpful to keep the cable in the shifter for tension reasons as J.B. Weld said. Even if you are getting a new cable in there (which can't hurt), leave that old one in until you get the shifter working. Pick yourself up a can of Clean Streak, it is the best cleaner/degreaser of everything I've used.
  • 11-30-2012
    NEPMTBA
    I have found in the past that WD-40 on old plastic tends to weaken it, not being a party pooper just passing on. I use 556 or Liquid Wrench