Variable suspension spring rates using magnetorheological fluid

A vehicle suspension control system comprising:

• a central suspension spring core;
• a first suspension spring surrounding an upper portion of the central suspension spring core;
• a second suspension spring surrounding a lower portion of the central suspension spring core, the first suspension spring and the second suspension spring coupled between a wheel and a fixed structure of a vehicle to inhibit movement of the wheel;
• a spring seat surrounding the central suspension spring core and coupled between the first suspension spring and the second suspension spring, the spring seat including an outer sleeve and multiple seals for retaining magnetorheological fluid between the outer sleeve and the central suspension spring core;
• one or more electromagnets adjacent the spring seat;
• and
• a suspension control module configured to energize the one or more electromagnets to selectively modify a viscosity of the magnetorheological fluid to inhibit movement of at least one of the first suspension spring and the second suspension spring,
• wherein the suspension control module is configured to selectively energize the one or more electromagnets at a specified first energization value where the viscosity of the magnetorheological fluid is sufficient to generate friction between the central suspension spring core and the outer sleeve of the spring seat to lock the outer sleeve of the spring seat in place along the central suspension spring core via friction.