Unwelcomed Growl from new GS4 DCC On-Board

[GARYBEAR]

I get a growling/buzz noise at mid boiler of the locomotive when putting DCC throttle to the new engine on the test track even if it is insufficient to cause it to move (as I haven't adjusted the start voltage).  This is quite unlike my B'mann Santa Fe Northern w/DCC On-Board.  Grasping the shell does not alter the buzz.  Add'l throttle causes motion and new noises but leaves the growl unchanged.  Furthermore, I hear a racheting sound when moving in reverse.  I haven't found anything externally amiss; and was utterly amazed that changing out the decoder for a silent operating Digitrax decoder failed to diminish the buzz.  Any ideas?  Thanks.

[ScottyB]

Well, I wrote an entire post about replacing the decoder, but if I would have read your whole post, I see you tried that! 

Sometimes if your command station and decoder are set to different speed steps, it can cause buzzing.  Other than that, I'm at a loss.

I've replaced all my stock Bachmann decoders due to buzzing, and this has solved the problem.  Best of luck to you!

Scott

[jonathan]

I'm sure I'm not alone, when I opine that it is difficult to offer ideas when receiving written descriptions of loco problems.  Be that as it may...

I can't speak to the buzzing.  I have run a couple of my Bachmann locos (with stock decoders) on our club layout (a digitrax system of some sort).  In fact my loco seemed to run quieter than other locos present.  Programming sure is a nightmare, though.  Even changing the address can give one agita (sp).

As far as ratcheting, here is another guess:  I have found it common that a driver wheel pick up brush can get get bent out of alignment and rub on the back of the spokes, causing a most distressful noise.  Yes, it can be that way when new.  Also, depending on how it's bent, it will 'ratchet' in one direction and not the other.  It's delicate work, but the brushes can be bent back into proper alignment.  Due to the small size and location, it can be easy to miss in a visual inspection.

Three of the six brushes were missalligned on this loco, but it was pretty easy to remedy, as long as you use a gentle hand.


Again, that's a guess.  Not enough info to guess better.

Regards,

Jonathan

[GARYBEAR]

Jonathan - Thank you so kindly for your reply--and image--as to the possible cause of the racheting noise.  I have captured it and printed it.   I made my plea on the Message Board to obtain real life responses like yours.  If I can visually confirm that the driver wheel pickup brush is the cause, I will not be in a rush to tear apart the GS4 as I expect to rarely operate this in reverse.  I am entertaining the possible disassembly of the locomotive to change out the motor which I suspect to be the cause of the buzz.  I could at that time deal with the wheel pick up brushes.