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. The screws are too long, they are about 0.195" in length, and need to be no longer than 0.150".

The supplied screws bottom out in the holes, so the keeper (00L06) from holding the brass bearing tightly.

Procedure: (courtesy Dave Goodson)

1) Remove all stake side boards from bed.

2) Remove box cover in bed.

3) Open one hood side. Flex radiator forward slightly at radiator cap, remove hood.

Open other hood and repeat.

4) Remove front screw holding down box into bed. Not the circuit board screw.

5) Turn unit over. Remove 2 rear cab screws. These are located in front crossmember of bed support.

6) Lift cab at rear, allowing box to flex up slightly. Pull cab back and undog cowl from firewall. Lift cab off and set aside. (You can access rear screw of box. This requires removal of switch, flexing of wires, and may not be something you want to do).

7) Remove 2 small screws holding floorboard down, one each side of gearshift lever. Lift floor and remove. If difficulty is experienced, lift seat straight up, remove on screw in bottom of seatbox and remove seatbox.

8) Remove 2 screws holding black support bracket to gearbox just forward of front u-joint assembly.

9) These are the problem screws. They are approximately .195” long, from under head to end of threads. They need to be less than .150”, which can vary with how deep the holes are on your unit. Cut off about .050” and file flat, or obtain new screws of proper length, and re-install. Make certain black support bracket is fully seated by pressing down and looking for air gap under screwhead. Washers should not be used as this will hold the floor up, preventing it from laying flat against frame.

10) Re-assemble in reverse order after lubricating gearbox.

As an addendum:

The screws provided with the snowplow are exactly the correct length.


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.


More tips:

Read George Schreyer's excellent page:


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