Several years ago I went to fire up my old 12E grader to plow some driveways. As I pulled away from where I'd parked I found the leaning wheel function didn't work. Temps the night before were in the teens and I finally figured out water in the leaning wheel box had frozen. A quick detour to home and a small propane torch gently heating the bottom of the box soon had it working again. Next step was to remove the fill plug and poke a piece of brazing rod down into the innards to try to find where a drain could be added.
Then it was time to drill and tap a hole for a 3/8" pipe plug. As soon as the drill broke through, water began to run out. Then it was time to tap the hole for the pipe plug. After that was done, I topped the box up with 80w90 and away we went. Now I crack that plug every fall and check for water. Since that time, no more problems with the leaning wheel regardless of temps.