Ideas on this sound?

[iBison]

07 v6 4x4 138k.

It sounds like it is coming from the back. Does this at all speeds, accelerating, decelerating. No change in 4 wheel drive, no change if engine is shut off. Gets higher pitched at higher speeds. Car drives straight no change with moving steering wheel at speed. Same in pavement and grass, thinking tires. Started while I was in Wyoming in September and has progressively gotten louder. It's not the rear wheel bearings. I had the fluid changed and I know it was changed by a previous owner once with synthetic I believe.

https://youtu.be/xBOEvpFBRYo

https://youtu.be/vd8vjLQT5t8

 

[Morphyne]

Well. How aggressive are the tires and when is the last time you rotated them?

 

[iBison]

AT3s it didn't change when I drove on grass leading me to believe it not a tire issue. It also happens at very low speeds.

 

[Seymore Butts]

What makes you so sure it is not a wheel bearing?

 

[OC2003]

What makes you so sure it is not a wheel bearing?

+1 sounds. Like bearing noise to me

 

[Morphyne]

Wheel bearing, differential, drive shaft needle bearing. Has to be one of those

 

[iBison]

We were pretty confident it was a rear wheel bearing. One of them was definitely on the way out but not the problem.

 

[2003-4x4runner]

When was the last time you changed the rear diff oil?

 

[iBison]

When was the last time you changed the rear diff oil?

September. It was also changed by previous owner don't remember mileage.

 

[fdbyrne]

We were pretty confident it was a rear wheel bearing. One of them was definitely on the way out but not the problem.

I'm confused. How did you rule out the rear wheel bearings? You say one was on the way out. Did you just replace both of them and that's why you're confident they aren't the problem?

 

[iBison]

I'm confused. How did you rule out the rear wheel bearings? You say one was on the way out. Did you just replace both of them and that's why you're confident they aren't the problem?

Yes.

 

[TowMeOut]

On the short video the "warble" sound was pretty pronounced even when you're going slow. I'd kind of rule out axle/wheel for that reason and go more towards driveshaft. Have you greased the driveshaft lately (u-joints and slip splines)?? If not that then it could be your pinion bearings starting to go.....

 

[iBison]

On the short video the "warble" sound was pretty pronounced even when you're going slow. I'd kind of rule out axle/wheel for that reason and go more towards driveshaft. Have you greased the driveshaft lately (u-joints and slip splines)?? If not that then it could be your pinion bearings starting to go.....

I ask them to grease it regularly when I get oil changes but can't guarantee they do it or do it right.

Thanks

 

[iBison]

We pulled the drive shaft today and the u-joints look good. We drive it in front wheel drive. Still makes the sound but not as loud. Now all the traction lights are on.

How big of a job is it to replace the pinion bearing? I'm thinking about looking for. - used center sectuon and just dropping it in.

 

[Ida4runner]

Pinion bearing?

 

[iBison]

Pinion bearing?

Yes.

 

[2003-4x4runner]

If it is the Pinion Bearing, then the sound should have stopped. At least that's what I've read here on the forums.