Aristocraft Dash-9 Gearbox problems

09/04/04

Aristocraft Dash-9 (also SD-45, E-8) Gear-box noise:

As noted on my Garden Railroad page, my new Dash-9 suffered from an apparently 'defective' front motor block as it ran choppy and was noisy.

UPDATE: (7/6/08) - Problem corrected

The U shaped power transfer strips that route power from the top circuit board to the + and - motor power leads on the motors can create downward pressure on the power lead side of the motors. This causes a binding when the motor block is screwed up secure against the truck frame and above circuit board. I had one motor block that was running choppy and finally after hours and hours of experimenting I found that if I installed the motor block in the engine (and took the bottom cover plate off) and used a flat blade solder tip and melted the solder on the motor lead ends while pushing down one the motor lead with the soldering iron I found the motors actually moved down into proper position. (showing they were pushed out of alignment) I repeated this on all four motor power leads.

Afterwards, the motor block ran perfectly smooth and silent.

What I think is happening at the factory is that the motor blocks are assembled and the motor leads are soldered in place with the block OUTSIDE of the engine (not installed). When they finally go to install the block, if U shaped power transfer strip isn't already perfectly pressed against the top of the block, it will get pushed down as it is pressed against the power transfer circuit board on the above truck frame. When the U transfer strip pushes down, it pushes the motor ends out of alignment and causes them to bind inside the gear boxes.

INSTRUCTIONS ON HOW TO FIX:

First, flip the engine upside down and only remove the bottom shell casing of the motor block. DO NOT remove the motor block from the engine. (note, mine in the photos below is out of the engine, but is still installed in the truck frame and is solid against the circuit board above which is the key to all this.)

Simply use the soldering iron with this type of tip till you soften the solder on each terminal. Be sure to apply some pressure down on the tab of motor block power lead to push it back into place.