I haven't tried WD-40, but will give it a shot. I spent a long time
figuring out that it was the upper pulley. Drivetrain noises are sneaky,
but I was able to reproduce the noise when I spun the upper pulley by hand.
Or rather, moved it. It didn't spin freely.
Thanks for the input, all.
As a footnote to this thread, I've noticed that the original lubricant -
usually some kind of grease - that the manf. uses for these items tends to
harden after so many years. I had a problem like this with some rapid-fire
MTB thumb shifters, too. Took 'em apart, hosed 'em out with PB
PB Blaster works well for that, too. I had a derailleur with some of those
pulleys that stiffened up like that and shot some of into 'em. Then I blew
out the excess with compressed air and replaced it wth Tri-Flow lubricant.
They almost spin by themselves now.
On Sunday, August 30, 2020 at
I have a M739 that has those "sealed" pulleys that squeaked. They
pulleys were quite stiff to turn by hand. I had never done any So I decided
to "play nice" and take one apart, clean thoroughly and relube with some
Phil oil. I put it back on the bike and it was still stiff. Well sheesh.
First of all, are you certain it’s the upper pulley? I’m asking because
I’ve never heard of nor experienced a Shimano ceramic bushing squeak
before, and especially after so many remedial actions too. I guess the
rubber lip seals, if run dry, may squeak, but if you oil/grease the
bushing, the
