Trouble with shifter

[outskirtscustoms]

I just got this GT Karakoam mountain bike with the Shimano Deore LX Rapid fire shifters and the right side (Rear 7 speed) shifter is not shifting, The bottom (down-shift) lever is not catching. I took the dust cover off the bottom and manually pushed the catch in and shifted it to the lowest gear and the up-shift lever works fine. Is there a spring inside that is off? Does it just need oiled? Can they be re-built or am I screwed?

 

[bikejunky]

Throw it away and replace it with a new one. The new one usually comes with a new cable (bonus).By the time you find the small parts to repair it, you will have more in them, then buying a complete unit.

Tim

 

[outskirtscustoms]

Do they still make this model? I want to keep the bike as original as possible.

 

[kingsting]

Super mega common problem with old RapidFire shifters. 99.9% of the time, it just needs blasted out with an aerosol lubricant. I like silicone spray myself but WD-40 works in a pinch. The little pawls get sticky with old grease. Spray it real well and work the pawls back and forth with an old spoke sharpened to a point (One of my favorite tools). Some need to be disassembled more than others to get at the pawls. Don't try to take the mechanisms apart, just remove the plastic cover(s).

If your real lucky it will come back to life with just a spray down and nothing will need to be taken apart.

 

[outskirtscustoms]

Super mega common problem with old RapidFire shifters. 99.9% of the time, it just needs blasted out with an aerosol lubricant. I like silicone spray myself but WD-40 works in a pinch. The little pawls get sticky with old grease. Spray it real well and work the pawls back and forth with an old spoke sharpened to a point (One of my favorite tools). Some need to be disassembled more than others to get at the pawls. Don't try to take the mechanisms apart, just remove the plastic cover(s).

If your real lucky it will come back to life with just a spray down and nothing will need to be taken apart.

That makes sense, I can manually push the paw in and it seems to work so I'll give that a shot. Thanks.

 

[jerrykr]

Good luck. I have a "Schwinn" and a real Trek with the same problems.
Tried the chemical cure. No joy.
Took one apart, you are a better man than I if you get it back together and working!
I am thinking that wear is critical on these things, and you can't cure wear. JMHO.

BTW: I too could shift it manually with the cover off.