I echo thurnderbird's sentiments, although this is probably not what you want to hear! A thick hard crust of soil which has not been broken up will give you long-term problems if you want to do any effective gardening, especially if your base soil is clay. You will have poor drainage, parts of your garden or lawn will continually become flooded or boggy after heavy rain, and any deep rooting trees or shrubs will eventually die because their roots cannot penetrate deep enough. Even if you have to dig a small patch at a time, it really is worth deep digging to break up the hard crust of soil. Once done well, you shouldn't have to do it again and the last thing you want to be doing is having to dig up your garden to rectify problems once shrubs and plants have been put in. Just regard it as a good calorie reduction exercise, and think of all the fresh air you'll be enjoying !