General:
    • Width, overall at rollers: ~1-9/16"
    • Width, center to center of rollers: ~1-3/16"
Rollers:
    • Width: 1/4"
    • Diameter, outside: ~7/8"
Collar, keeps centered in track, mounted above nut on threaded post:
    • Diameter, outside: 7/8"
    • Thickness: ~1/4"
Vertical post:
    • Diameter, outside diameter of threads: ~5/16"
    • Nut, flats: 1/2"
    • Length, below nut: ~1-1/2"
    • Length, overall, included spring loaded roller support: ~2-1/2"
Bracket, mounting:
    • Width: 1/2"
    • Length, overall: 1-1/4"
    • Height: ~15/16" (see Warnings & Notes tab)
    • Diameter, outside of bushing: ~1/2"
    • Diameter, inside, female threads: Matched to ~5/16" threaded post(see Warnings & Notes tab)
    • Mounting hole spacing, center to center: 15/16"
    • Mounting hole diameters: cleared for #8 fasteners included
Fasteners: (4) #8 SMS x 1-1/4" included

1) Thread pitch may have changed requiring a swap out and use of the included new mounting brackets.

2) The mounting bracket cylinders are dimpled where they transition to the flat section with the holes for mounting to the door. The threaded shaft can pass beyond the dimpled section by holding the bracket in a vice or similar and using an open ended 1/2" wrench on the nut to rotate the shaft. Some installations have the mounting bracket cylinders recessed into the sliding door, opposite that shown in the photos.

Either way, start by chasing the shaft threads through the brackets with the cylinders towards the nuts. If needed remove the brackets and flip over, with the goal to match the bracket depths below the rollers to the depths originally used.