for positionable in and out movement in a direction transverse to the longitudinal axis of the kiln 10 to this purpose the bearing housing structures are mounted on a base 29 for movement thereon by means of adjusting screws 31 and 32 which are connected to the base 29 through adjusting lugs 34 and 36 as shown in fig1 the opposite roller support 17 arrangement is duplicated on the opposite side of the rotary kiln 10 by an arrangement identical to that of the roller support 16 arrangement referring now to fig2 a cross section of the downward bearing housing structure 27 shows a bearing housing 41 and a closure plate or end cover 42 a bearing bushing 43 is disposed within housing 41 and arranged to provide a rotatable lubricated support for the downward shaft 23 an alignment indicator arrangement generally indicated at 46 is disposed within the closure plate 42 to respond to thrust of the downward shaft 23 to this purpose the closure plate 42 is provided with a machined bore 47 the axis of which is parallel to the axis of the shaft 23 in forming the bore 47 a circular shoulder 48 is constructed a deflectable displacement disc 49 of the diameter of the bore 47 is disposed within the bore abutting the circular shoulder 48 abutting the displaceable disc 49 is an axially extending hub 51 of a movable piston 52 housed within the bore 47 of the closure plate 42 the piston 52 is provided with a radial flange 53 that is received in a counterbore 54 formed in the closure plate 42 a thrust washer 56 having a plurality of radially extending oiling grooves 57 is secured to the axial inner end surface of the flange 53 of the piston.