I've got this old two row 25B working but I don't understand how everything works. On the John Deere 24B and 25B cotton and corn planter parts list Page 16 Part# 40. It calls the part "Wheel, cotton feed". I've never planted cotton so I don't understand. It kinda looks like a small circular saw blade. The shaft runs in two nylon bearing, Part #39. I've got one unit working pretty smooth but the other is very hard to turn due to this nylon bearing wearing out. It works great when I take it out. I found new bushings I think will work. I am not going to be planting cotton, so I don't think I need it. Just want to know how it works and what it does??