I cannot get my left castor wheel off! The first time I tried to lower the deck, the pin was nearly rusted in place. I used wd40 to clean it and a coat of fluid film to prevent further rust. Today, I coaxed that same pin out (with a big hammer) and now I can't get it back in. The green frame for the wheel is pretty much wasted now from me hammering on it. I'm wondering if the pin that runs through the bearings is bent....but I haven't hit anything with it. The mower is a little over a month old. Should I ask for a new castor assembly??