I read a lot of posts about leveling front to back with the tongue wheel. Doesn't that only work if the front is lower than the back to start with, so the tongue wheel can raise it up? I have the opposite problem in my driveway - tail end sinks down. What do I do for that? This is only a driveway problem, but I need to keep it in the driveway from time to time for cleaning, measuring, packing and unpacking, etc. Thanks for any advice.