I think the sleevs he is talking about is this one:
on the left side.....it is a thick collar sort of deal pressed on.....
versus this one that doesnt have it (on the right)
There are several old threads about this and in fact this forum saved my butt when I was inquiring on the same thing not long ago.....turns out it was done at the factory when the stock bushings/sleeves werent tight enough in the hole on the arm.
I was told that as long as the main bushing sleeve is tight in the bore, you can run without them. I had to cut mine off to get it off so I could get the bushing sleeve out.
I soaked it in PB Blaster first and then ended up using a chisel and small cutting wheel to make a notch in it, then used the chisel to expand it and get it off.
Hope that helps a little....