Adjustable split thrust ring

A well drilling system, comprising:

• a housing defining a longitudinal dimension;
• a driveshaft positioned within the housing, wherein the housing and driveshaft are operable to slide relative to one another along the longitudinal dimension, and rotate relative to one another, and further wherein the driveshaft has a groove surrounding a circumference thereof;
• and
• an adjustable split thrust ring positioned between the housing and the driveshaft, the adjustable split thrust configured to transfer an axial load between the housing and the driveshaft, and including;
• a downhole split ring including two or more separate downhole pieces, the two or more separate downhole pieces fit together to form a substantially circular downhole shoulder;
• an uphole split ring positioned proximate the downhole split ring and including two or more separate uphole pieces, the two or more separate uphole pieces fit together to form a substantially circular uphole shoulder;
• and
• a wedge positioned between associated ones of the two or more separate downhole pieces and the two or more separate uphole pieces, the wedge operable to travel radially to move the substantially circular downhole shoulder and the substantially circular uphole shoulder relative to one another to adjust for changes in the groove shape.