Forney operation problem

[MRRSparky]

I've had this loco a couple of years in the box, never run.  When I finally got some layout wiring done, I pulled the loco out to run it on a test track.  The headlight did not work, so I started checking continuity and all was good except for the connection from where the blue and yellow wires terminate on the side of the Bachmann board  to the 8-pin plug.  On opening the tender, a number of very small parts fell out, looking suspiciously like surface mount resistors.  They might explain the dead headlight.

Having done a bunch of hard-wire DCC installs in HO, I decided to remove the Bachmann boards and wire the Soundtraxx decoder to the OEM wiring harness.  Now the headlight works.

In testing the final assembly on a set of rollers, I noticed that the tender "jacks" up and down (an oscillation) with each rotation of the drivers.

Folks on the On30 Conspiracy Group suggested that the drivers are possibly out of round, mounted improperly on the axles, or the axles are bent.

I really don't want to send this to Bachmann to fix so can I buy a set of drivers for this loco? Sorry for the long-winded intro.

Scott Groff

[MRRSparky]

I decided to remove the drivers, one at a time, to check for wobble. In doing so, I
found that all three screws on the driver bottom plate were loose, thus not
clamping the drivers securely in place.

With the drivers not secured in their bearing slots, the main and side rods
would torque the axles a little up and down in the bearing slots. I put the
loco upside down in a foam cradle and ran power to both sides of the trailing
truck. I could immediately see the problem.

With the first axle out and checked, it showed a minor amount of
non-eccentricity but not really bad. So I reassembled things.

BTW, the nuts that secure the rods do not match 000, 00, 0, 1 or 2 nut drivers.
They must be metric, so I had to use my metric pliers to remove/replace them.

Now with the loco reassembled and axles secured, the loco not only runs better
but much of the gear noise is gone. The motion down the track is kind of like
what you see when a real steam loco kind of "hunts" its way side to side down
the track. There's not enough that I want to go further trying to fix driver
wobble.

I also found that two of the four sand lines were rubbing on the rear driver while operating in reverse.  Cutting them loose from where they were glued in cured the problem on one side and some CA glue solved the one on the other side.

I considered sending the loco to Bachmann to fix but I have spent some time altering the loco: added the included coal to make the plastic coal load disappear: added a backup light and carved both of the B lamps to look like A's; added an engineer; added front and rear brake hoses; and removed both Bachmann PC boards, at the same time as re-doing the tenuous wire connections to the Soundtraxx board. What prompted  that was that I found the blue common wire loose and the white wire hanging on by one strand.  No wonder the headlight didn't work.

Past experience with Bachmann in HO scale is that they will replace the loco
with this kind of problem rather than spend the time fixing it. I really didn't
want to redo all this on a new loco.

This has been quite the adventure.

[Anubis]

Well done, for sorting out this problem, solo.

I agree with you that Bachmann would not accept it back, due to your mods. Besides, you wouldn't want to do them all again, would you?

(Yours must be a Friday-afternoon build....)

You should have lots of trouble-free running with your Forney, now.