Does XT have a guide pulley? I'm not 100% certain that it does.
(*edit* I meant to say, "Does XT have a guide pulley with lateral movement?"... of course it has a guide pulley, whoops)
Either way, if one has a bushing and the other a bearing, the bushing will be the guide pulley. It's also usually cast/printed onto the pulley wheel itself if you look closely, at least with the Shimano ones.
Originally Posted by
Tandem Tom
One other thing. I notice that one wheel spins much more freely than the other. I think the 'centeron' is the one that seems stiff.
If both are clean, undamaged, and properly lubed... one shouldn't spin noticeably better than the other. Even if one is a bearing and the other a bushing, it shouldn't be all that noticeable when you spin it with your finger. If one is noticeably slower, that sounds more like it has more grease or more built up dirt than the other...