To Make a Dimensional Constraint Draggable (AutoCAD Mechanical Toolset)

If the Parameters Manager is not visible, click Content Editor tabManage panel Parameters Manager.
In the Dimensional Constraints Parameters section, in the row corresponding to the dimension to make draggable, double-click in the Drag Grip column.
In the drop-down list, select where you want the drag rips to appear.
The preview in the Content Editor updates.
In the Minimum column and the Maximum column, specify the possible minimum and maximum values for the dimension, if applicable.
The edge associated with the dimension is now draggable.