This paper has two goals. The first one is to discuss two related packing problems in the Lee and Manhattan metrics. One is to find good codes for error-correction (i.e., packings of Lee spheres) and the other is to transform the space in a way that volumes are preserved and each Lee sphere (or scaled cross-polytope) will be transformed into a shape inscribed in a small cube. The second goal is to consider weighing matrices for some of these coding problems. Weighing matrices have been used as building blocks for codes in the Hamming metric in various constructions. In this paper, we will consider mainly two types of weighing matrices, namely conference matrices and Hadamard matrices, to construct codes in the Lee (and Manhattan) metric. We will show that these matrices have some desirable properties when considered as generator matrices for codes in these metrics.