Refitting Aristo-Craft Locos with Ball Bearing Motor Blocks

Aristo locos that use or can use the 2 axle ball bearing type of motor block include the FA1/FB1, RS-3, U25B, RDC, and EggLiner. The RDC and EggLiner were too new to have had the old version 2 axle sleeve bearing type motor blocks. (The Aristo GP40 has a shorter wheel base 2 axle ball bearing motor block of different design.)

Shown below is an example early version RS-3 that has been refitted with ball bearing motor blocks that allows adding more weight for improved traction. The loco already had been fitted with centerset Kadee couplers.
Those other Aristo locos that use the same motor blocks can be similarly upgraded, albeit with differing interface wiring.

Aristo-Craft and successor, PolksGeneratioNext, are out of business; however, Bachmann currently makes a replacement 2 axle ball bearing motor block that is used in their Bachmann resurrected Aristo EggLiner. This motor block can be used for retrofitting the Aristo early version locos.

Because I already have several ball bearing motor blocks that Aristo sold sometime ago having stainless steel wheels, albeit with reduced flange depth, I could not justify getting the Bachmann block for now.

That said, the blocks are virtually the same except for wheels & some cases electrical connectors, and as such, the methods for fitment are the same as described in the fully detailed vignette (article) hosted for me by Greg E. on his Web site, title:
Upgrading Aristo-Craft Loco Motor Blocks from Sleeve to Ball Bearing

-Ted