Name that Sound - Drivetrain while accelerating

[abright52]

This noise just started today, I jacked it up front and rear, but couldn't see anything obviously wrong.

2007 Tahoe LTZ 4x4
Just under 100k on it.

No noise if acceleration is gradual.
No noise when revving in park or neutral.
No noise in reverse.
No noise at higher speeds (30+).
No noise with rear tires in the air.

I am fairly certain that I have a bad front passenger wheel bearing, I am planning on ordering that tomorrow...probably get a couple of U-Joints, as well.

 

[Jesburban]

Motor mount?

 

[abright52]

Well, that is one thing that I hadn't thought of. I did power brake it and no noise...I would think the motor mount would make noise under those conditions?

 

[Jesburban]

I'm no expert, so I dont know if it would. You should be able to see it though, have someone else power brake while you watch. My friend had the exact same noise, and it was the drivers side motor mount. Sounded exactly like yours.

 

[abright52]

Thanks, I will check it out.

 

[abright52]

Just wanted to update:
Replaced both U-Joints on the rear driveshaft and that seems to have fixed the issue.

The rear U-Joint was noticeably dry and seized...probably what was causing the sound.