Cause of mild whining in 6th gear between 40-55mph when accelerating.

[dday]

2009 CX-9 Touring AWD has a mild higher pitched whine when hitting the gas between 40-55 mph. Using the manual shifter, I can attest that in 5th there is no whine and it also doesn't do it at higher speeds in 6th.

 

[batmancx]

2009 CX-9 Touring AWD has a mild higher pitched whine when hitting the gas between 40-55 mph. Using the manual shifter, I can attest that in 5th there is no whine and it also doesn't do it at higher speeds in 6th.

some suspects to look at :

1) bad wheel bearing

2) PTU (transfer case) leaking

http://www.mazdas247.com/forum/showthread.php?123847373-Changing-CX-9-transfer-case-gear-oil-%28photos%29

3) need to drain and fill transmission oil

 

[dday]

some suspects to look at :

1) bad wheel bearing

2) PTU (transfer case) leaking

http://www.mazdas247.com/forum/showthread.php?123847373-Changing-CX-9-transfer-case-gear-oil-%28photos%29

3) need to drain and fill transmission oil

Thanks! Dealer looked at it today. Said they could hear it driving, but wasn't loud enough to be able to tell where it was coming from when they got it up in the shop. Advised to drive for a while and check back if it gets worse. They said transfer case wasn't leaking and didn't think fluid drain and fill would impact the noise.