Hi there, I hope to find answer to my question about my CRV 2006. Recently was serviced for flushing the rear axle to eliminate the sound. Whatever that is I don't understand. Is it necessary though?

Are you talking about flushing and replacing the transmission fluid? If that's the case, I'd like to hear an explanation of how that could change the sound.

As for CRVs in general, I know two people who have them and like them.

If your rear differential was making a growling or grinding noise when turning, they most likely flushed out the gearbox and changed what Honda calls "Dual Pump Fluid". They call it that because of the design of the "on demand" AWD differential. It has internal oil pumps that actuate clutches to provide traction in either forward or reverse. I have read that this oil has special additives that will break down over time and cause noise. I never had this issue on my CRV, but recently changed the fluid anyway. I did not not flush the unit, just drained and installed new fluid. It had 60K on it at the time and was quiet.

I was actually looking for info on upgrading the stock speakers for the doors of my CRV when I spotted your RE.
Bugman was right on, but would like to add this just happened to me last week on my 06 EX CRV.
It was grinding in the front and when I took in 2xs the noise would not reproduce. 2 weeks ago it started in the back and was really loud. It was covered under warranty but we ony have 5k before our 36k warranty is gone. I think this is a band aid fix to a problem with the AWD system.
They flushed the gear box in the rear. They say it can get rough spots on it (similar to a rotor getting spots). They flushed it and the noise stopped.
My concern is that you have the problem too, and how much will this be when the warranty is up?
How many miles was on your car when this started?
Do you have an EX?

As far as the car, my wife loves it and we have 3 neighbors with older models that are still running great. Our is the only AWD though. We have towed a boat for 2 summers with it and it does a pretty good job pulling.

Henry your question is interesting as well as the suggestion but you did not mention if the problem was answered.
This is a good technical issue for us car dealer.