A bearing block assembly includes a liner having a two piece ring of low
friction material extending around the rockshaft and held in place by a
bearing block. The rockshaft includes a radially projecting member
interacting with the bearing block assembly to maintain the axial
position of the rockshaft. The bearing liner includes a flange extending
beyond the bearing block to contact the projecting member. The flange is
seated in a groove at the side of the bearing block and lowers the
coefficient of friction at the rockshaft/thrust surface interface.