The article presents the results of the work area focused on improvement of the sealing packages of the roller cone bits for high speed drilling. Long term experience of running low speed bits with sealed oil filled bearings demonstrated that even with such rotation speeds seals remain the most critical area limiting the bit durability. Based on the analysis of the designs of the sealing packages as well as main reasons resulting in loss of sealing in the bearing assembly of the roller cone bits during high speed drilling, it was determined that one of the options of upgrading the seal life is the decrease of the frictional moment of the seal. The seal located in the bit bearing possesses certain axial dimensions, therefore for its installation it is required to reduce the axial dimensions of the bearing. However, reduction of the axial dimensions of the bearings lowers their carrying capacity. In view of this axial dimensions of the seals must be as low as reasonably possible. Also, increase in their radial dimensions is undesirable because it results in increase in the friction radius and leads to enhancement of the frictional moment. Having said that, it is also necessary that the seal should be inexpensive when manufacturing and assembling the bit. The seal cost increase must be economically feasible, and its durability must exceed the bearing durability only in a minor way. It was determined that a considerable drawback of end seals and end-radial seals is interrelation of their operating practice and depreciation due to the wear of axial bearings where end play of the cone increases. When moving the cone onto the journal the pressure in the end contact increases resulting in the grow of the moment in the seal. At reverse motion of the cone the pressure in the end sealing contact decreases that may become the reason for the seal failure of the end joint and leak of the fluid in to the bearing.