>>1750892The shifters work via a ratchet mechanism. If the teeth of the ratchet wheel get gunned up, they won’t ‘catch’. If the pawl gets gunned up and won’t spring back towards the wheel, it won’t catch.
Either take em apart and clean them with tooth brush and cleaner (and then re oil them). Or just spray we-40 in them like other anon said, and work them around.
