I have an assembly made of 4 parts which make an extruded aluminum window frame. I need to use this sub-assembly in multiple places when designing window systems. I have a sketch in the extrusion's assembly from which the length of each part is derived. When I update the sketch, the rest of the parts update also.

The problem is when I load this sub-assembly into the design library It won't update the length after I insert it into a new assembly. The line changes length but the rest of the parts will not. Any way to do this?

I need to be able to drop multiple instances of this subassembly and each have a different length.