My 2009 Grand Caravan C/V with 60K miles has a noise and now a slight vibration that increases with speed. Putting it in neutral at speed has no effect. When turning, the noise does not get better or worse. Its loud at 50MPH+. Its hard to pin point the source of sound while driving...My best guess is in the front, about in the middle left and down. I checked the wheel bearings on all 4, and no play at all. I continue to drive it and the noise and vibration are getting worse. Its still totally drive-able though.

Checking CV Axles: Boots all look good. Drivers side axle is un-moving, solid, no play. The much longer passenger side axle does not move when you yank on it perpendicular to the shaft. However, if I push/pull on it, in and out, it has some play to where you hear it "clunk" in and out.... not huge, but there is play.
Question: Should there be no play at all, like the drivers side?

 

How did you check the wheel bearings? Did you spin the tires as well as check for tilt?

Does the sound go away when you apply the breaks or does it just slow down with the speed of the vehicle?

Is there any sign of uneven wear on the tires?

LMHmedchem

 

Raised the tires, checked for play in all directions. Solid, Smooth, no movement. No bearing sound or grinding when rotated.
Applying brake has not affect upon the noise or vibration
No tire wear issues. Even rotated the tires to see if the noise followed the tires....no change.

 

Can you describe the noise? The suspensions on these are really simple, especially in back, so there are a limited number of things that could cause issues.

The area you describe where you think the sound is coming from is where the transmission is. Have you checked to see if there are any warnings or codes in the computer?

LMHmedchem

 

The sound is difficult to pin point... Its seems everywhere, like the front of the vehicle was overall making noise. But it does seem to directionally peak down and left of center. A passenger will point to that same area...roughly. Its sounds like a bad wheel bearing. I was convinced it was a wheel bearing. Now that the noise is a vibration too that can be felt on the steering wheel and on the gas pedal, I thought the wheel bearing would be destroyed and it would be easy to confirm....but again, all 4 wheels are smooth and solid.
The noise does not change even when shifted to Neutral at high speed. The Trans shifts and operates just fine, no codes. Engine RPM is not a factor. It is absolutely 100% tied to wheel speed.

 

Question: Should there no play in the passenger side drive axle; left/right, up/down, in/out?