Bottom roller replacement:
Remove the 5/16-18 x 1 3/4 Hex Head Bolt (HHB) [1], lock washer [2], flat washer [3], and roller [4].
Apply medium-strength thread-lock compound (for example, blue Loctite®) to HHB. Replace the roller [4] and eccentric bushing [5]. Install the components in the opposite sequence they were removed. Make sure the roller [4] is tight against the V-rail [6].
Rotate the eccentric bushing [5] until the roller is tight on the rail.
Torque the HHB [1] to 20 ft-lb (27 N-m). Apply Mobil 460 grease to the bottom V-rail [6].