Abstract: A rotary index table assembly including an annular positioning mechanism (22) that cooperates with a lift mechanism (140) to accurately position a rotary index table (14) on a base (12). The annular positioning mechanism (22) includes a base mounted crown gear (24), a table mounted crown gear (26) and a movable crown gear (28) that is moved out of engagement with the base and table mounted crown gears to permit the indexing rotation and that is thereafter moved into engagement with the base and table mounted crown gears to locate the table with respect to the base while the lift mechanism (140) supports the table on the base by the movement of the movable crown gear (28) to permit the accurate positioning.