Looking for input on this one.
Just for argument's sake, say this noise was at least 400Hz, while the AL4 was kicked down and accelerating hard towards 50MPH.
It's not the wheels or wheel bearings (too high a frequency - I checked with rough calcs). My impression was that it came from within the gearbox. Motor was plenty warm, and so was the trans fluid.
Could it be something so simple as a mismatched gearset that will never get better, nor really go away? It's a rebuilt box 20 000 (kilometres) ago with nine months of warranty left, but I don't have a lot of confidence in the rebuilder's ability to address a warranty claim of this type.
The only thing which particularly bothered me, was that I've not noticed it so clearly before. Then again, it was a pretty hot day (33°C) and possibly the hardest I've driven the car on a hot day so maybe fluid viscosity had dropped further, allowing better sound transmission...
Regards, Adam.
Rotational Noise Under Acceleration
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