I have an iR_Advance_C5051 that I have been struggling with. There is a 1.5 to 2 millimeter skew on grid test chart 6, but only out of the paper deck. All output from other cassettes are fine, and the second side of prints out of the deck are fine as well, so it's not the registration roller. I have looked at and cleaned the rollers in the deck pickup assembly, swapped feed rollers from one side to the other, and even "adjusted" the spring tension on the one paper sensor that I thought might be causing a problem. I took the side door off the host machine (where the paper from the deck passes through it) to see if I could find any warping or obstruction. I even took it apart to check the spring-tensioned rollers inside. Nothing. Put it all back together and still getting the skew. Then I tried pushing on one side, then the other of the paper deck as it fed paper to see if that would make any difference. Nope. The spring tensioned flap at the exit is straight and parallel to the mating surface, with the approximate typical 1/8 inch gap, the small white plastic rollers that contact the host machine are good, and the springs are all in place. The separation sponge rollers look new, and the feed rollers that contact them, though not new, are in good shape. (Those are some of the ones I swapped as well). I swapped the smaller outrigger pickup rollers as well (the ones with the metal bases). No change in the skew.
My next step will be to try new rollers throughout and a new separation torque limiter...
My next step will be to try new rollers throughout and a new separation torque limiter...