If I coast down to say 40 km/hr (25 m/hr) and then apply the gas slightly more aggressive than smooth, I get a screech. If I apply the gas too aggressively or too smoothly, I don't get a screech.

I will paypal $20 to anyone who can diagnose this accurately, so that they can buy 2 beer.

Possibilities:

1. Fuel system pressurizing or starting up.
2. A vacuum system.
3. VCM turning off.
4. Screeching fan belt (but I can't replicate this in neutral).
5. Transmission downshifting.

Go!

 

My gut says it's axle related.

 

Getting rear diff fluid changed next week. Will let you know.