An older MTB has a [Shimano ST-EF500 shifter](https://planetcyclery.com/shimano-st-ef500-3-x-8-speed-brake-shift-lever-set-black/) or a very similar one. It is for a three speed front derailleur. It will not shift from the middle chainring to the largest one.
I was going to check cable tension and the limit screws but I realized the shifter didn’t click when trying to go between the middle and largest chainring. That made me think the issue was old lube gumming up the mechanism. This was, in fact, the problem with the rear shifter. However, I flushed the shifter mechanism extensively and it doesn’t seem to correct the issue.
I noticed that when shifting from the middle to largest chainring, it takes pushing the shifter button much longer before it engages the mechanism than with the shift from the smallest to middle chainring. By the time I’ve pushed the button as far as it will go, the mechanism with the teeth in the shifter can’t rotate enough to click into the next position. I attached a video attempting to show this.
I checked different bike with a different model of Shimano shifter and it seemed to engage the mechanism for both clicks with the same amount of button pushing.
What should I check next?
How should I further troubleshoot a front trigger shifter that won’t click to shift from middle to large chainring (doesn’t “click”)?
byu/geoffreyhing inbikewrench
by geoffreyhing
10 Comments
Disassembly it completely, and fix spring tension.
Firstly it needs cleaning, just so you can guarantee nothing is being held by it
It’s probably a stuck pawl, so you are missing a click. The original grease gets sticky over time. Do not fully disassemble the shifter. It is very likely not spring tension.
Spray some isopropyl alcohol in there, take a pick and poke the little moving bits, there will be one hidden underneath a bit that looks like it engages with the teeth on the ratchet ring, wiggle that until it moves freely and spray more alcohol in.
I relube with dri slide moly lube, but you may not jeed to. If you do, do not get it on your skin, the solvent it is suspended in and the molybdenum isn’t great for you. Click it a lot to make sure it works and lube is evenly distributed.
Where is the pawl?:
On the left hand side of the shifter in the video, on the part that moves when you push the lever, there should be a little stuck doodle bop that can move but isn’t and is supposed to spring back and engage with the teeth on the ratchet ring. Maybe right hand side, but I think left.
As much as I support keeping existing stuff working correctly…why not just buy a new 3×8 left hand lever? They’re incredibly cheap…
Dude, it’s full of shit. Clean it entirely (take it all apart and degrease all the metal shit, wash out all the plastic shit and let fully dry), and regrease the greasy parts. Put it all back together, and it’ll be your bottom bitch.
OP here. I was able to fix this. As u/CargoPile1314 and u/dasklrken pointed out there are two pawls and the one I didn’t know existed and was ultimately stuck was the one one left, near where the cable enters the shifter body.
Thank you to both those users for helpfully annotating a screen grab of my video to show me where to look for the other pawl.
Things I wish I would have known/done initially:
* Loosening the shifter so I could rotate it on the bars was really helpful for better seeing the different pawls and being able to access them and squirt cleaner on all the different moving parts.
* Watching more videos where the person actually agitated both pawls. The [Park video I watched](https://www.youtube.com/watch?v=DSlj28P6IZA) just showed squirting cleaner and lube into a port in the shifter without even taking the cover off. Having a better sense of the structure of the shifter and where to look for moving parts would have helped me make sure I was agitating all the pieces.
I have the same model of shifter, it was really dirty when I opened it for the first time because it had the same problem as yours, cleaned everything I could and put new grease on everything that needed it.
Now it still works flawlessly after 2 years.
I don’t know if this would help you, I hope it does
Remove/replace. Shimano shite not meant to be serviced.
Depends how patient you are! the proper fix is a complete tear down, grease and re-assemble. It’s not easy and it fiddly, but it’s the best fix.
The easier fix, would be to flush it with wd-40, then flush it with de greaser, followed by a plastic safe lubricant (not wd40).
Wd40 is great at breaking down old grease and flushing out crap, but it’s not good long term on plastic and nylon parts.
It’s filthy. Wash it with loads of WD-40. Clean the Derailer. Lubricate everything with not WD-40. Then try and see if it works. Then replace the cable.