A boom assembly including a boom defining a longitudinal direction pulley rotatably mounted on a pivot pin, the pivot pin having a first end with a first outer surface and a second end with a second outer surface, a pulley frame having a first part for receiving the first outer surface, a second part for receiving the second outer surface, a first hole for receiving a first adjustment rod and a second hole for receiving a second adjustment rod, the boom including a first receiving portion for receiving the first adjustment rod and a second receiving portion for receiving the second adjustment rod, the boom assembly being configured such that adjustment of the first and second adjustment rods causes movement of the pulley in the longitudinal direction.