Abstract: An improved motor grader circle mounting and circle assembly has a mounting in which an annular upright wall with an outwardly extending integral top flange and a removable bottom flange form an outwardly open annular cavity. A circle structure of welded arcuate segments is rotatably mounted between the flanges and cooperates with the wall and flanges to form a close annular lubricant chamber, and a segmental internal ring gear is on the circle structure in the cavity. Renewable segmental lower and upper bearing plates are located between bearing surfaces of the circle mounting and the circle; and a lower oil sealing ring is so located as to permit removal of the bottom flange and lowering of the circle structure to replace all the bearing plates and a segmented upper oil seal without draining the lubricant chamber.