Screech and chatter at low speed - Bachmann DCC OnBoard FT-A

[NKTower]

I have Bachmann 44-tonner, doodlebug and EZ-Command DCC. all work fine.  Just added a Bachmann FT-A w/ DCC pre-installed and while it runs fine and quietly at moderate speed, at low speed it screeches and chatters.  Is this the nature of this particular model series, or is it a problem to this particular model and thus due for repair or replacement?  It's a week old, purchased new via mail order.

[ACY]

It is a low end DCC loco, not a Spectrum, don't expect a ton.

[K487]

NKTower:

I've got 3 of the Bmann FTs and yes they are on the low end of dcc locos and yes they all did their own variation of the "screech act" out of the box. 

I disassembled them all down to where I could access all the internal moving parts and lubed them (particularly the motor shafts' bearings) with light plastic-compatible oil.  Problems fixed.  Ran them (DC, I don't use DCC) in some, changed couplers to KDs, and they are very good pullers (believe it or not just one of these FTs can pull a 61 car train by itself, even though I use two so I don't over-stress one.)  The engines are also surprisingly quiet (not as quiet as Atlas though.)  After lubing, these have been very good bangs for the bucks for me.

K487

[NKTower]

Thank you for responses.  I think I have some LaBelle 108 in one of my boxes, it definitely is worth giving it a try.