Noise between 35-45mph - Please Help

[Groundgrubs]

2008 CX-9 AWD. 90,000 miles

Did a transfer case swap with suction pump in and out, let it overflow, then capped.
Did a transmission drain and fill - only got 3.5 quarts out of the transmission, added back exact amount.

Noise did not seem to be there before all this -

Now under smooth acceleration, between 35 and 45mph, I get a whine/vibration/sound different, goes away at 45 and does not depend on the gear, does it in 3rd or 4th. Performance does not seem to change at all.

If I hard accelerate nothing happens, or is so short that I can't hear it.

Any suggestions?

 

[batmancx]

2008 CX-9 AWD. 90,000 miles

Did a transfer case swap with suction pump in and out, let it overflow, then capped.
Did a transmission drain and fill - only got 3.5 quarts out of the transmission, added back exact amount.

Noise did not seem to be there before all this -

Now under smooth acceleration, between 35 and 45mph, I get a whine/vibration/sound different, goes away at 45 and does not depend on the gear, does it in 3rd or 4th. Performance does not seem to change at all.

If I hard accelerate nothing happens, or is so short that I can't hear it.

Any suggestions?

What brand and oil type did you use for transfer case ? Also when was the last time you changed the rear differential fluid ?
It can also be a faulty wheel bearing, it's a common issue on high mileage CX-9

 

[Groundgrubs]

More info

What brand and oil type did you use for transfer case ? Also when was the last time you changed the rear differential fluid ?
It can also be a faulty wheel bearing, it's a common issue on high mileage CX-9

Transfer Case was changed with Royal Purple 5W20. Same one named in many posts regarding Transfer Case process

It definitely is coming from the front, have never changed the rear differential - It was next, but now with this, might leave to experts.

I can throw a jack under it and feel for either wheel bearing play over the weekend.

 

[batmancx]

"5W20" ???? you meant 75W140 right ?

I just swapped mine two weeks ago and then did it again this past weekend to try to get the remaining sludge out,
both times with Royal Purple 75W140 without any issues or whining. I don't think just by adding new oil that would cause whining noise.

 

[Groundgrubs]

"5W20" ???? you meant 75W140 right ?

I just swapped mine two weeks ago and then did it again this past weekend to try to get the remaining sludge out,
both times with Royal Purple 75W140 without any issues or whining. I don't think just by adding new oil that would cause whining noise.

YES Sorry for the typo, i was thinking about the oil I used....