I don't own one, but Sam'sTrains on YouTube has one, and in his video it works on 18 inch radius (technically second radius which is the same thing).

Hello everyone,

I have a Bachmann BNSF DCC Ready GP40 that I bought back in 2021. Straight out of the box it was a noisy runner, jerked along at really slow speeds and had a really bad lack of torch. When I first bought it and found this issue and oiled the model. This temporarily fixed the issue, but after a few months it ran poorly again. I opened the model up again and oiled it, but this time it didn't fix the issue. I stoped running it for a while, as I was sick of dealing with its issues, but not long ago I tried running it, and it seemed worse than before. This time I removed and cleaned every gear and linkage, and ran some rubbing alcohol through the motor, but this did nothing. After that I powered the motor directly, and it was still quite noisy, however it seemed more smooth (for obvious reasons I couldn't check the torch while doing this). I own three other GP40's from Bachmann, so I know this is not normal, as my other ones work far better. If anybody has suggestions to solve this issue, I would be happy to hear them. Thanks for taking your time to read this far!

I've never owned a Bachmann sound locomotive, but on most models CV 8 and 9 control that.