I just took my 2004 Simplicity Regent (1693915) out of the garage for the first time this year. After making two passes on the lawn, the tractor stopped moving. It acted like the bypass lever had poped out. I can either push the lever in or pull it out but the transmission won't engage. Everything looks to be conected. Now when I restart the motor and my foot off of the brake I heard something spining in the transfer case but there is no movement what so ever. Any ideas?