One of my 47s was from the original batch which dragged on track and the body a bit high.
It's been a bit troublesome over the years, not mechanically but the bogies have never been spectacular so I replaced them about a year ago and it seemed to make things worse - to the point I would not run it.
My intention was to fit sound to both of my 47s but the body is a bit more complicated than my other non sound Farish locos - the lighting is under the cab area so my go to method of remove cab interiors for a speaker and stay alive floundered as I would lose the lights. With the new Next18 chassis now available I've waited till I could get a decent price for one and I've taken the plunge. I was going to get a cheap one from Rails (the Colas non sound) but when I added up the chip and sound file from Digitrains it was more than the cost of a sound fitted one. TMC had an offer on some of their sound ones plus an extra 5% so I took the plunge for £211 I got a sound class 47 and put on a BR Blue body. First thing, Bachmann have added an annoying switching sound when you change ends and the sound is currently very loud, but quite impressive too. I can see the lighting channels have altered slightly, leading to a dimmer red light plus this loco has a light passage for the headlight too so I need to switch that off which I hope is in the functions, if not I need a bit of tape. Loco is not run in yet either.
I am going to wait now and see what comes next from Farish for the next releases of 47s in case there is a blue with headcode or green full yellow ends.