A seal seat is mounted in the housing and includes a face surface for slidably engaging the annular nose surface of the seal washer to form a seal
. The mechanical seal is positioned on the shaft relative to the housing such that the seal washeris urged against the seat by the spring force of the belleville washers. In this position, the seal washer is displaced rearwardly toward the lug holder such that the shoulders extending from the seal washer do not engage the tines.