Derailer Pulley Question

[Litho]

Quick question for everyone.  I have a nice XT derailer that I'm swapping over to one of my bikes, but am having a problem with squeaking coming from the upper pulley.  I love the derailer, but actually removed it from another bike because the squeaking was driving me nuts.  I tried everything I could think of but it always came back.  My efforts included: 

• Removing the pulley and cleaning it thoroughly. 
• Lubing it with oil. 
• Lubing it with grease
• Removing all lube and running it dry. 
• Taking it apart again.  
• Trying each of the above several more time.  

I haven't replaced any of the parts yet.  It's a ceramic bushing in the pulley, not bearings.  Any suggestions?  Any recommendations on better pulleys I could swap in?  

Erik   

[Benz Ouyang, Sunnyvale, CA]

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 rubber seals will inevitably be coated too. Come to think of it, did you install the metal pulley end caps “inside” the rubber lip seals?

In any case, if you’re looking for replacements, pretty much any replacement with the same pulley size will work. I like the Tacx ones, but there are others, like from Velo Orange. In all cases, you’ll likely lose the lateral float function of the Shimano ceramic bushing; but if your derailleur is adjusted spot-on, you shouldn’t have a problem.

Good luck!

[Garth]

 

   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. So the other one I decided to just squirt some WD-40 and both sides and work it in, so to speak. That one started spinning freely quite quickly, so I sprayed the other one too and it was now spinning freely.  Three cheers for squirting WD-40 directly in the pulleys.... zero cheers for taking them apart and trying to be all "proper" about it.

   So try squirting some WD-40 on both inner sides and spin 'em around.

[George Schick]

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.

[George Schick]

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 Blaster, blew out the remains with compressed air, and replenished with Tri-Flow.  The started working perfectly again.  Also, this appears to be a common problem across the product lines with Shimano in particular.

[Litho]

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. 

Erik