Jaw crusher with toggle plate tensioning feature and associated method of crushing rock

A jaw rock crusher comprising: a first jaw; a pitman; means to cyclically move the pitman along an eccentric path; a toggle plate disposed adjacent said pitman on an opposite side from said first jaw; a means for adjusting a location of said pitman so as to control a maximum size or material which is permitted to pass between said fixed jaw and said pitman; a tension rod assembly coupled to said pitman and configured to create a force which is biased toward increasing contact between said pitman and said toggle plate; said tension rod assembly comprising a spring which is displaced during operation of the means to cyclically move the pitman; and an indicator disposed remotely with respect to a gap between said first jaw and a bottom portion of said pitman, wherein said indicator configured to provide an indication of a separation distance between said first jaw and said bottom portion or said pitman while simultaneously providing an indication or operation of the means to cyclically move the pitman.