John Deere L130

I had the mower on an angle so I could replace a bad tire on the back right. After the new tire was put on and rolled down to a level place mower would not go in forward or reverse, the pin in the back was in the correct position, is there and easy way to fix or do Es it now need taken to a repair shop?

Look around were you removed and worked on the rear tire. Sound like you have lost the square key that goes in the groove on the shaft and in the rim.