Abstract: An automatic transmission assembly is constructed or modified to minimize effects of wear thereon and maximize its operational life. The assembly includes a transmission case and has a modified ring-shaped center support that is to be secured against rotation within the transmission case. A center support plate, which is attachable to and detachable from the ring-shaped center support, includes protrusions thereon that engage between cooperating protrusions defined on the transmission case to secure the ring-shaped center support against rotation within the transmission case. The invention is particularly useful when the modified ring-shaped center support is a worn, original equipment support that has deteriorated in function. A process of modifying an automatic transmission assembly is also described.