I have an older bobcat zt100 mower. There is a gear box that has sheared off 3 of the 4 bolts. I need to be able to take this box out in order to fix it. However, for me to do that I have to remove the wheel that is attached to the shaft coming from the box. (The wheel drives one of the belts.) I have removed all the obvious points, such as allen screws and such. There is appears to be a square pin that may or may not need to be removed? (See the picture below.) Anyway, I just need to know how to remove this wheel. Thanks for you help!