If you mean the cylindrical plastic bushing that slips over the pedestal, yes. It is most likely a 2 7/8 seat bushing with a lip and is available at most marine stores. Bring your old one.
If you are referring to the white plastic straight pieces then allow the seat to slide forward and backward, that is a different story. They are hard to impossible to find. These is a thread on this forum from a person who managed to find a replacement but the site didn't work when I tried to check it out. The manufacturer of the seat is not the manufacturer of the slide mechanism. Based on my efforts to fix, the bushings, manufacture new ones, or replace the seat slide, replacing the slide is the better option. Befog doing so, make sure you can remove the old slide. The mounting nuts are molded into the seat bottom and if they turn when trying to remove the slider, the job becomes very complicated to remove and replace the slider.
