Chambeador, from chamba, work, describes someone very hardworking and devoted to the trade. The Diccionario del español de México of El Colegio de México gives the example “el maestro albañil es tan chambeador que no se cansa” (the master bricklayer is so chambeador that he never tires).
Fajarse con el trabajo is to take on hard work with energy. Partirse el alma, “to split one’s soul,” means to make a great effort.