A movable jaw mounting assembly to provide retraction and positional adjustment of a movable jaw of a jaw crusher relative to a stationary jaw, the assembly comprising: a load bearing support frame to couple at least part of the assembly to the jaw crusher, the support frame having a part with a force transmission wall configured to transmit impact loading forces from the moveable jaw to the support frame; a toggle unit positioned between the force transmission wall and the moveable jaw, the toggle unit having i) a first toggle end for attachment to the moveable jaw, ii) a second toggle end for mounting in opposed relationship to the force transmission wall, iii) a toggle beam forming the second toggle end and iv) a toggle plate positioned between the first toggle end and the second toggle end; a pair of actuators attached at a respective first end to the support frame and at a respective second end to the toggle unit so as to provide a pulling and/or pushing force to the toggle unit to change a separation distance between the second toggle end and the force transmission wall; characterised by: a toggle holder in the form of an extension connecting the second end of each actuator to the toggle plate such that the toggle plate and the toggle beam are capable of being moved towards the force transmission wall by the actuator to retain pressure on the toggle unit in retraction; and a mounting attached securely at each end of the toggle beam to abut the toggle holder when the actuators are operative to move the toggle beam away from the force transmission wall in adjustment. a load bearing support frame to couple at least part of the assembly to the jaw crusher, the support frame having a part with a force transmission wall configured to transmit impact loading forces from the moveable jaw to the support frame; a toggle unit positioned between the force transmission wall and the moveable jaw, the toggle unit having i) a first toggle end for attachment to the moveable jaw, ii) a second toggle end for mounting in opposed relationship to the force transmission wall, iii) a toggle beam forming the second toggle end and iv) a toggle plate positioned between the first toggle end and the second toggle end; a pair of actuators attached at a respective first end to the support frame and at a respective second end to the toggle unit so as to provide a pulling and/or pushing force to the toggle unit to change a separation distance between the second toggle end and the force transmission wall; characterised by: a toggle holder in the form of an extension connecting the second end of each actuator to the toggle plate such that the toggle plate and the toggle beam are capable of being moved towards the force transmission wall by the actuator to retain pressure on the toggle unit in retraction; and a mounting attached securely at each end of the toggle beam to abut the toggle holder when the actuators are operative to move the toggle beam away from the force transmission wall in adjustment. a toggle holder in the form of an extension connecting the second end of each actuator to the toggle plate such that the toggle plate and the toggle beam are capable of being moved towards the force transmission wall by the actuator to retain pressure on the toggle unit in retraction; and a mounting attached securely at each end of the toggle beam to abut the toggle holder when the actuators are operative to move the toggle beam away from the force transmission wall in adjustment.