A system for detecting changes in the operating condition of frame assemblies of an agricultural implement includes a main frame assembly and a sub-frame assembly coupled to the main frame assembly, with the sub-frame assembly being configured to support a plurality of ground-engaging tools. The system also includes first and second load sensors configured to provide data indicative of a load applied through respective first and second portions of the sub-frame assembly, and a computing system communicatively coupled to the first and second load sensors. The computing system is configured to monitor the loads applied through the first and second portions of the sub-frame assembly based on the data provided by the first and second load sensors, and determine that a change in an operating condition of the sub-frame assembly has occurred based on a differential between the loads applied through the first and second portions of the sub-frame assembly.