Let's play 'Name That Tune' (or noise). I need some help identifying this noise. It not always present, but occurs when I press the gas. Sometimes it's softer, sometimes louder. In the video, when it stops, it's because I let off the gas. What do you think?

 

I'll play! -- Heat shield, exhaust crossover near the cross-member. Look carefully for a broken tack weld, pry lightly with a screwdriver. Had to re-weld a couple on mine.

 

I agree. Try putting a couple of gear drive hose clamps around that heat shield.

 

 

Have you checked, was that it?

 

It looked OK to me. A shop checked the heat shield and said it wasn't loose. Another couple of people thought it was wheel bearings. Those were replaced, but the noise is still there. Tuesday they'll replace the pinion bearings. I'll let you know how it goes!

 

Well, when the shop went to replace the pinion bearings, they saw that the pinion gear was missing a chunk out of it. So, that is likely where the noise is coming from. The gears will be replaced early next week. I hope to have a picture or two.

 

Sometimes a chunk can get whipped up in the oil, get caught in the gears, and it feels and sounds like the car ran over a 55 gallon drum. Were these the OEM gears or replacement gears that failed?

 

They are Yukon 5.13 gears.