The squeeky derailler pulley gets the grease

My cross bike recently developed a mean case of squeak. I figured out it was the derailler pulleys. They get pretty wet and dusty, so I can't blame them. To pull them out, I first removed the chain (since I've got a SRAM Power Link this is easy, can't recommend that enough) and undid the hex shoulder bolt (shown in the picture below). It's a Shimano Deore derailler, by the way. I figured that I'd have to lube the bushing, but after messing with the parts, I figured that the cause of the squeak was debris and a lack of lube between the side plates (silver discs shown below) and the pulley. I greased those, slid it back into the derailler, tightened the shoulder bolt, and removed it's brother. Only do one at a time unless you want to also disassemble the derailler cage. 

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I just had another thought on this subject.  Be careful with how much you tighten the shoulder bolt.  Too tight and you'll pinch the pulley, making it hard to spin.  Test it as you tighten.