if I am catering a Shabbos job can I ask my goyim to load the truck after the shabos meal if not can they load it on their own or do I need to tell them that they are not allowed to load the trucks
You should tell them that they should not load the trucks. The reason is that although it might be part of their responsibilities, and it can be argued that they are doing it for their own convenience. The same way a maid may wash the floors on Shabbos, since it is part of her usual responsibilities. Loading the truck however is something that can appear as if they were specifically asked to do on Shabbos, therefore they should not be doing it.