It is becoming increasingly common for manufacturing design teams to be composed of members belonging to the same organization, yet located in geographically different places. This has significantly increased the need for better support of synchronous communication among team members collaborating over a design. Unfortunately, there is a considerable technological gap in the support for collaborative, synchronously communicating mechanical CAD systems. In this paper we describe a prototype system, CoCAD, that provides a number of features that support synchronous collaboration among a number of mechanical CAD engineers located at different sites. Some of these features include the ability for each person to edit a design, the ability for each user to customize their local view of a design, the ability for each user to share a common view of a design, a shared pointer, the ability for someone to join in the middle of a design session, and object ownership and access permissions.