One of the major problems with the Aristocraft G-Scale locomotives is the wheel blocks. Specifically the U25B, FA-1, and FB-1. The wheels themselves were chrome plated and over time the chrome plating peels off causing electrical pick up issues. In addition the wheels are not wired directly into the pickup, the ends of the wheel pass the track pickup to frames and from there they are electrical wired into the motor. This causes problems and the engines over time do not reliably run.
Bachmann makes a block wheel replacement that uses a nickel plated wheel that lasts better over time. In additional the electrical pickup is built into the wheel block and transferred via wires to the locomotive. The wheel block takes some adapting to fit on the GE U25B locomotive. I ordered the wheel block from eBay but there are other options. The item is a Bachmann Remake Aristocraft 29351 Diesel Motor Block RS-3, FA-1, FB-1, U25B.
By adapting the wheel block the electrical pickup to the motors is significantly improved and locomotive runs better on all tracks.
Here is a step by step process on replacing the wheel blocks.
1 – Remove the existing wheel blocks. Pull the frames back from the end of the wheels and pull out the wheel blocks. The wheel blocks float in place in the frames via the ends of the wheels, no screws need to be removed
2 – Cut the 2 wires from the existing wheel block and the 2 wires attached to the frames. Leave as much wire to work with has possible.
3 – Cut the plug from the new block on the Bachmann wheel plugs.
4 – Attach the wires per the following color codes using solder and shrink wrap wire covers.
4 – Set the new wheel blocks in and drill a small hole into the locomotive at the attachment for the wheel block
5 – Put in 3/8” nuts as spacers to lift the wheel block to the correct level
6 – Install (2) screws to mount the wheel block through the spacers.
Enjoy the improved reliability of the locomotive.