Ok, so my $300 of self control lasted a day, and my reward was an e-revo that doesn't roll. I guess that's god saying "I pity the foo with 24 hours of self control."
Anyway, sounds like the middle tranny or u joint is grinding. I disengaged the spur and pinion and the noise persisted. The grinding happens less frequently than one revolution of the spur gear, so it must be further along the gear reduction. The car will not roll, the friction is too great.
I opened the box, charged the battery, put in my receiver, drove it 10 feet, and the problem was obvious.
I don't want to investigate any further because I want to return it.
Here is a video: