EF-29's are low end trigger shifter/brake lever assembly that came on my 2002 Trek 4500. The 8 speed rear shifter has ceased working properly. I can shift into larger sprockets fine from any position, but it won't shift into the smallest three sprockets. The trigger moves properly, but it doesn't index.

I've disassembled it (and discovered they almost certainly weren't intended to be disassembled outside the factory) and haven't found anything obviously wrong, but I think the indexing spring has gotten weak.

Is anyone intimately familiar with these shifters with further suggestions, or should I just buy a replacement?

I see replacement shifters (I'm looking at Sram Attacks...their Shimano compatible trigger shifters) come with cables already attached...am I correct that I can just thread these through the existing cable housings on my bike? Anything else to know about installing new shifters?

Thanks

Sometimes just opening the case and flushing with spray solvent frees up the sticky little ratchet parts. I resurrected my current shifters from the junk bin by doing this. As far as replacing, you can get away with using the old housing if it's not trashed, but for a few bucks you might as well take the opportunity to replace with new. Sheldon has a wonderful article on housing installation. BTW some shifters include new housing.

Try flushing it out with WD-40 or similar and hope it's just "gunk".
That's about the only "fix". Actually works quite often.

Thanks...I'll try the WD-40 first.

New shifters, even Shimano's low end stuff, will come with all new housing and cable for the shifters, and if applicable, cable and housing for the brake levers. If you've worn out your shifters through use, your cables and housing could use a refreshing as well.

Actually, looking closer and fiddling with it some more, I think the housing ferule is falling apart. I'm going to try replacing the housing and maybe the cable, too before I buy shifters.

Also look for a frayed wire on the DER cable that may be binding things up.

I know this is an old post, BUT did you ever find a fix for these shifters? I have the exact same problem on three (yes three!) Shimano EF-29 shifters on three separate bikes; they shift fine in gears 4,5,6 and 7 but refuse to use gears 1,2 and 3. Weird. Anyhoo, would love to hear if there's a fix. Cheers.

Obviously there are more possibilities than shifters here. The best shifters in the world won't shift if the derailleurs aren't adjusted properly.

FIXED!! The thumb shifter is connected to a hammer/trigger that drives the ratcheting gears. The spring that pulls the hammer into the smaller set of gears (in this case, 1, 2 and 3) needs lubricant and pressure to work the hammer back into position.

SO, 1) Remove all cable tension. 2) Remove the shifter cover plate. 3) Apply a drop or two of lubricant to the spring assembly where the thumb shifter is attached to the hammer. 4) Use a really small flathead screwdriver to push the hammer into the gears it's missing while the lubricant works itself in.

This may take several attempts, but just keep running through the gears and use the screwdriver to force the hammer into the teeth it's missing and it will eventually right itself. This technique saved five Shimano EF-29 shifters (left and right) for me. Good luck!