[ki5ka]

I recently bought a 6 year old, but never ridden bike. The trigger on Alivio shifter has been not engaging on some shifts. The problem was caused by 6 year old grease causing the pawl to sometimes not engage.

I was hesitant to disassemble the shifter to clean it properly because of posts warning of the complexity and difficulty getting it back together. It proved to be simple, but I only removed the downshifting mechanism, since that's what I was having problems with, and took photos to assist in reassembly.

Here's the order of what I did.

Remover the bottom cover plate. One screw
loosen 10mm nut - Left hand thread
lift "downshift" lever out of housing
Remove bushing from shift lever
Remove c clip from pawl
Remove pawl
Remove spring. Note smaller hook engages lever, larger hook engages pawl.
Clean with alcohol, then automotive paint prep. The alcohol left a waxy film. The paint prep takes film off and leaves no residue.
lubricate
reassemble

I started to disassemble the upshift mechanism as well but quickly changed my mind. I can see that it might become difficult to keep parts oriented correctly without some reference.

 

[Becane73]

I had a similar problem. I opened it up used WD-40 to clean out the dirt and old grease. Used an air hose to blow out the gunk and repeated a few time and oiled. Shifted like brand new after that.