Large Scale Central

Bachmann 1:20 Railtruck Procedure: IMPORTANT!

Modeling Rolling stock
#1

Tearing down 5 new Railtrucks (3 here, 2 at Barry’s), we have discovered an issue which in most probability will result in failure of the output gears in the transmission (gearbox) of this unit.

The screws in question (from the parts breakdown list provided with the unit) are Kader Part Number SCREW-10644.

These are about .195” in length from under the head to end of threads. They need to be no longer than .150”, and probably for manufacturing tolerances, about .140”.

The screws are bottomed out in the holes. This prevents the keeper (Kader 00L06, I think it says) from holding the brass bearing firmly in the housing, allowing extreme wobble and gear un-mesh in the output bevel gears, which shall result in failure at some point.

Procedure:

  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 removel 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.

We are still working on the surging on grades, two paths in work at this time.

TOC

Published with permission of Bachmann Industries. This notice must be attached to any copies.

#2

Dave (T0C)

Many thanks for all of your work in problem solving.
Am I accurate, from your experience, to implement the solution above, about 20 minutes or less is involved?
Granted, those who are more cautious and less experienced in taking a loco apart may need more time.

Wendell

#3

Yeah, I timed at 15 minutes.
Someone unfamiliar will take about 30 minutes.
I didn’t put that in initially for fear it would scare some used to instant gratification.

#4

Dave-

I “instantly” feel better.
Thanks,
Wendell

#5

Mine had the long screw affliction as well, but I’ve hacked around the surging problem

see Bachmann Railtruck Tips

  • gws
#6

Very cool George. Do you know what Barry’s fix is? Did you consider shimming the motor end play?

Regards, Greg

p.s. nice to finally meet you in person at BTS!

#7
George Schreyer said:
Mine had the long screw affliction as well, but I've hacked around the surging problem

see Bachmann Railtruck Tips


George, thanks for the link. You have a very interesting and helpful website.

#8

Dave,

Thank you for the crystal clear instructions. I recently purchased a new Rail Truck from Trainworld and used your instructions to check for the aforementioned long screw problem. The screws in mine were indeed .195 in length, but were not bottomed out and the bracket in question was tight. While I was in there, I changed out the screws with the snowplow screws as suggested anyway and added a lot more grease to the gears. Thanks again.

#9

I’ve thought about buying one of those but I’ll have to remember this!

Thanks

#10

I did Dave’s modification and mine has been great.

#11

not too many people on this planet that understand mechanical issues and good fixes as well as TOC…

#12

Bob
Could the first part of this post ,be put in the Article section like a sticky?