The digital transformation (DT) is reshaping the economy and society. In supply chains (SCs), DT involves adopting digital technologies to collaborate. DT opportunities are particularly diverse in globally distributed manufacturing networks (GDMN) and SCs. Here, DT influences both internal and external collaboration activities, i.e., configuration and coordination of the intra-firm network and network relationships, structure, and governance in the inter-firm network. This study investigates if and how DT changes relationship dynamics and collaboration efficiency in SCs and distributed manufacturing networks through information sharing and jointly used digital technologies. While existing studies have mainly focused on individual digital technologies and their potential for SCs and manufacturing networks, this study contributes to a better understanding of the adoption process and the change in relationship dynamics through DT and joint use of digital technologies. The methodology follows a qualitative approach in a multi-case study setting with six multi-national manufacturing companies operating extensive intra-firm and inter-firm networks. A theoretical framework based on organisational information processing theory guides the study. Data is collected in semi-structured interviews and enriched by secondary data from internal company documents and publicly available sources. The results indicate that digital tools are triggering a centralisation trend in intra-firm networks that leverages efficiencies but is met with stakeholder scepticism. SC collaboration is becoming increasingly dynamic through digital tools, which the SC partners often promote. Non-adopters are not being dropped yet, but the pressure of digital transformation is increasing and becoming more of a threat to small businesses.