Abstract: Track rollers are mounted to the track frame by brackets having mounting holes which are asymmetric relative to the roller shaft. This permits the rollers to be mounted in alternative positions along the frame, by turning them end-for-end, for the purpose of altering the pattern of wear caused on the track links when the links impact the rollers and for reducing impact vibrations by altering the roller spacing.

Abstract: An operator's mounting step structure for a crawler-tractor includes a step housing having a floor or bottom formed by a downwardly and outwardly inclined surface of a track-tensioner recoil spring housing. The surface of the housing inclines downwardly and outwardly and a primary step is spaced above an outer portion of this surface so as to leave a gap between the foot-engageable member and the surface to prevent dirt and mud and the like to gravitate down the surface of the housing and through the gap. The housing of the step structure further includes a top wall which has a forward upturned lip which forms a secondary step spaced vertically above the primary step. The top wall is curved downwardly and inwardly from the upturned lip thereof and it joins the recoil spring housing at an inward location of the downward and outwardly inclined surface.