Often the grease fittings are plugged with paint, make sure that grease is flowing to the pin. Please specify which end of the dipper you are concerned with, it does sound like the top end. If the bottom, do you have a thumb? Make sure that the dipperstick doesn't hit the boom in the corners when fully extended, mine did just that so I relieved the boom corner radii with a carbide burr. You might want to remove the bolt and try to move the pin with a punch and light blows with a hammer, if it is tight you need to find the cause such as galling or defective parts. These backhoes were produced in Georgia by folks that don't deserve a job.