I work in a small rural center with only 13 routes and 7 employees on the morning pre-load sort. One of us unloads the semi, one SPA's, one dumps smalls and does surepost, and four people load the packages into the trucks. Previously I was the floater who dumped smalls and did surepost and I was also trained as the feeder shifter who would move the semi off the building before our second one came and then also switch the 2nd and 3rd trailers if we had 3. I've done this for 3 years or so. Well, one of our preloaders with more seniority than me was getting so many misloads that they almost got fired. Their solution was to say that they should have my job because they had more seniority. So far management seems to be going along with it, and they moved me to a preload position. The problem is that this other person is not trained to shift the feeders. Actually, I'm the only person on the sort who is. But now, I have to leave the pull to move feeders and all my trucks get stacked up and jacked up as packages go by and others try to stack them in front of my trucks or put them away for me (poorly at times) while I'm out moving the feeder. It's not fair for me or the other pre-loaders who have to try and cover the slack while I'm gone. No other pre-loader has ever had to pre-load and shift trucks like this. If I'm not going to be the "floater" anymore who does smalls and surepost then I don't want to have to shift the feeder anymore because that was a part of the initial reason why I got trained in it in the first place, so that I could be the floater. What is the proper way for me to resolve this? Can I just tell them I no longer want to shift the feeder if they make me do preload and then just not do it, or do I have to do it until my certification expires, which I think is a yearly thing? What are your thoughts?