I haven't been using my bike that much lately, and last time out both shifters were playing up- the levers wouldn't return after shifting and I had to push them back into the ready position every time.

So my question is- is it worth opening up the shifters and poking about, or are there 100 tiny parts/springs that will jump out as soon as I do and make me wish I'd just got new ones? They're LX shifters and have worked fine for nearly 4 years now.

You probably just need to replace your cables, as they sound like they've rusted up or something, and aren't moving as freely.

Give them a good blast of GT85 or similar. I presume the mech is returning OK?

New cables before you do anything else.

don't attempt to take your shifters apart unless you are a shimano robot with special shimano robot spring putter-inner fingers. 🙂

You probably just need to replace your cables, as they sound like they've rusted up or something, and aren't moving as freely.

I'm pretty sure it's not the cables, or rather not just the cables. Shouldn't the levers spring back even with no tension in the cable?

No

don't attempt to take your shifters apart unless you are a shimano robot with special shimano robot spring putter-inner fingers.

Does everything stay in there when you open them up, long enough for a squirt of GT85? The mech is fine.

Not if the cables are sticking in the outers and stopping everything moving freely.

There must be something in the lever though to make it return- when you move up to a bigger cog, say, the cable doesn't move again to bring the lever back after the shift…?

When the lever moves, the cable obviously moves with it. If the cable is sticking, the lever is going to have a hard time moving.

you can take the tops/outer casings off most shifters. But have you ever come across a component called the ping-fukkit? you don't want to lose any of those.

I'd usually take the cables out and spray GT85 in through any available gaps.

When the lever moves, the cable obviously moves with it. If the cable is sticking, the lever is going to have a hard time moving.

The lever moves, the cable moves, the mech moves, and the gear change is done no problems. But then the lever doesn't spring back ready for the next shift, and that bit's not dependent on the cable is it…?

So sometimes the levers move independently of the cable.

old shimano grease sometimes gets very sticky, so one or other of the little pawls and springs isn't able to overcome the resistance and do its job. GT85 will usually soften the grease and hopefully the return springs will start working, but it's far easier to tell if the cable is not in the lever.

Here's what's inside… 🙂

Mine had the same trouble on the thumb push lever – had to flick it back with my index finger after shifting. It was sticking due to general kak buildup inside the shifter. Undo the screws you can see on the outside and take the top of the shifter off (nothing will pop out unless you pick at the mecahnism), pick out anything obvious (being careful not to dislodge anything that may pop out), squirt with some flavour of lube, reassemble, whizz up and down the gears a few times to work the lube in and all's well.

The cables were fine as evidenced by the perfect shifting after lubing the shifters.

Thanks thepurist and all, will get the GT85 ready.

i had a problem with the lower half of the shifter casing losing the bolt (older one bolt model) replaced the bolts and they work ok now.