Worn Derailer Pulley Question

[henmar77]

I have a XT Shadow Derailer installed. I have been trying to diagnose ruff shifting issues forever. I pulled the upper pulley (the one closest to the cogs) and notice that there is a significant amount of side to side play. This didn't seem normal to me considering one of the steps to tuning is making sure that it lines up with the large and small cog. Its kinda hard to do this when the pulley is moving side to side. So should it be tight or is play normal?

[vanamees]

Play is normal.

[henmar77]

great then i dont know what the hell the problem is then..

[RSabarese]

I would recommend a few things to try; first if you undo the cable, does the shifter run through the gears smoothly? If so, then I would move onto the cables. First, are they routed without sharp bends (even if the bike came out of the factory that way)? If that's all okay, how old are the cable housings? Replacing them also with a fresh inner cable should make things smoother if they are older. One other note, Shimano puts a thick grease in the shifters, if they are not smooth, you could flush the shifter with WD-40, then clean it up and add new grease. I have done this with mine, but I use tri-flow, a light oil with PFE, they shift like new.

[J.B. Weld]

There are probably 100 different things that can cause poor shifting, RSabarese touched on several above. Without knowing any specifics of the problem I would start here-

Make sure derailleur hanger is straight, you may have to run it by a shop and have them check it with a tool.
Cables and housing, one of the most common causes of shifting woes in my experience. If it hasn't been done in awhile I'd just replace them- cable and housing.
chain and cassette clean and in good condition?

Once the above boxes are checked then it's usually just a matter of setting the limit screws and adjusting cable tension.

[zebrahum]

There are probably 100 different things that can cause poor shifting, RSabarese touched on several above. Without knowing any specifics of the problem I would start here-

Make sure derailleur hanger is straight, you may have to run it by a shop and have them check it with a tool.
Cables and housing, one of the most common causes of shifting woes in my experience. If it hasn't been done in awhile I'd just replace them- cable and housing.
chain and cassette clean and in good condition?

Once the above boxes are checked then it's usually just a matter of setting the limit screws and adjusting cable tension.

Nothing important to add to this. These are, in order, the most common causes of shifting problems. Investigate these and you will almost certainly find your problem.

[robselina]

lots of miles on this bike? As Henmar said, Some movement is normal, but it shouldn't be excessive.

I have had to replace derailleur jockeys on two derailleurs in the past due to wear. Once the bearings go, they can wobble off axis and can cause erratic shifting.

That being said, the more common items listed by rsabarese, jb, zebrahum should generally be investigated first.

[J.B. Weld]

Pulleys shouldn't wobble (much) off axis however the upper pulley is designed to move from side to side about 1 mm or thereabouts to help line the chain up directly under the cog even if the cage is slightly off.

[fahza29er]

Define rough shifting, does it shift up fine to a certain point then make alot of noise? Is it just down shifting? Does it chatter while riding in any or all gears? Everyone has a different cause and cure. Does it hesitate to shift up or down, all gears or just the top or bottom 3-4? What level is the derailleur and shifters, XT, X9 just an example. Does it hang while trying to say shift up to the top 2 gears on the back cassette?

[Bro]

What level is the derailleur and shifters, XT, X9 just an example.

It's right there in the OP: XT Shadow derailleur.

To the OP: make sure that the derailleur cage isn't bent. If the cage doesn't line in a parallel line to the cassette cogs, it's toast. That is, after you've checked all the other things that everyone else has mentioned.

Diagnosing shifting problems over the internet is really tough. It's a bit easier to see what's wrong when you have the bike right there in front of you.

[J.B. Weld]

Diagnosing shifting problems over the internet is really tough. It's a bit easier to see what's wrong when you have the bike right there in front of you.

No doubt! 20 seconds of seeing, hearing, and touching the problem = about a 1000 words of description.