Need more advice. Dropped it off at Startech today. They were unable to reproduce the noise. This does not surprise me too much since the conditions have to be precise--downhill grade and just enough throttle to unload the drivetrain. Plus, it's real windy today so it would be very hard with hear with the wind gusts being what they are.
Anyway, on the lift, they can detect no bearing noise but they think it might be the axle joints and are recommending replacing the axles with rebuilts. They say the grease in the axles is dried up. What does everyone think?
They say there is no detectable difference between the two sides of the axles. The noise is definitely on the right side with no noise at all from the left. The noise has been there for at least a year and is slowly getting louder.
Would bad CV joints only show up when unloaded? Why does the noise only occur unloaded?
Here's a thread where the problem was the wheel bearing:
http://www.peachparts.com/shopforum/showthread.php?t=112604&highlight=ron+young+300td