pads 30 may in a further embodiment be of a u201c spiral u201d configuration 37 e g curvilinear parallelogram as represented o fig4 a to facilitate better wear patterns and rotational motion to the plunger assembly 10 each half retrieval neck 24 has an annular ring 38 on its inner open end as represented in fig3 this ring 38 engages a lip 40 on the distal side of the curved sealing surface pads 30 and keeps them secured to the central spine or mandrel 12 at each outer or respective distal end of that split pad plunger 10 as is represented in fig3 an arcuately segmented split retainer ring 50 preferably of semi circumferential shape as represented in fig1 6 is disposed about the mid point of the central spine or mandrel 12 and has an annular lip 52 which secures the other or u201c proximal u201d longitudinal edge 54 of each curved sealing surface pad 30 in proper location about the central spine or mandrel 12 each set of split retainer rings 50 is held in place around its respective longitudinal mid portion of the central spine or mandrel 12 by a bolt 56 extending therethrough with an elongated adjustable lock washer 58 as represented in an u201c exploded u201d configuration in fig1 each set of split rings 50 has an elongated slot 51 in each ring 50 u2032 as represented in fig6 the adjustable lock washer 58 shown best in fig7 receives the bolt 56 as is represented in fig1 and as is represented in phantom in fig6 the washer 58 has at least one movable lock tab 60 thereon as represented in fig7 for easy manipulation.