Bachmann Rail Truck How to improve the drive train. The rail truck is a fine model, but many run noisy or erratically out of the box.The problem is the bracket that holds the worm gear in the drive train is often not completely tight and this allows the mesh of the gears to be erratic, often resulting in premature wear or stripping.Once you have the model open (remove stakes, box cover, hood, and the screw that holds the bed, 2 screws underneath that hold the cab, and 2 screws that hold the floorboard) look at the black bracket just in front of the u joint. The screws that hold this bracket are too long and bottom in the hole before they tighten the bracket tightly.Some people have found they can just tighten the screws down really hard, but the best thing to do is remove about .05" from the screws and put them back in. Don't put washers under the screw heads, you will have a clearance issue with the floor when reassembled. DCC installation: DANGER! WARNING! Do NOT believe the Bachmann wiring diagram, not all rail trucks are are wired the same! The basic instructions have you remove 3 wires from a terminal block. The wires in 1 and 2 are supposedly the motor leads, and the wire in 3 is the ground for the common wired LEDs. Then the terminals 1 & 2 are used for track pickup connections. On a recent model, the motor leads (directly from the motor) were not soldered as per the diagram. This installation, by George Schreyer, worked as per the drawing. On an early model, the motor leads were soldered into the M+ and M- pads, and this did NOT work, apparently there was still some internal connection between one track pickup and one motor lead. The Zimo decoder used just went to full speed at any speed step. Luckily it did not melt down. Once the motor leads were removed from the circuit board and directly wired to the decoder, all was well. The leds were still powered from the track, and we left it that way. My suggestion is to do the same thing, do not trust the Bachmann wiring. We encountered the same "internal" connection on another Bachmann loco, the consolidation. The decoder used, the Zimo 642 works great and is a HO decoder and we used the Galloping Goose sound file, which is a free download. There's more to do to set the file to have the horn on the F2 key.