An improved modular disc cutterhead connecting drive shaft configuration having a means for laterally centering the shaft between adjacent cutterhead modules thereby equalizing engagement on each end of the shaft with the module connectors. Further durability improvement is realized by a structure to radially center the shaft in the shaft receptacles of each module to maintain uniform loading on the shaft/receptacle interface which improves the durability of the connecting drive shaft end connections. Additional connecting shaft durability is provided by a means to lubricate the drive shaft connector connecting interfaces using lubricant reservoirs disposed within the modules.