Rotational Squeak/Rattle Coming From Drivetrain

I finally got a decent recording of the sound. It's faint, but you can hear it best toward the end of the video. It's much louder in person.

It sounds like a dry bearing. Sort of like when the sleeve bearings in a electric motor get dry and it starts to make that screeching sound.

It only makes the sound when there's load on the drivetrain, but not too much. Too much gas and it goes away, let off the gas and it goes away. It sounds like it's coming from the middle of the vehicle.

Can't be the center support bearing (often erroneously called a carrier bearing) because I don't have one (reg cab).

I've lubed all the u joints.

Any ideas?

https://www.youtube.com/watch?v=_rExV_J6Zf0

 

If I’m hearing the right noise, it sounds more related to wheel speed...

 

Have you checked to see if your axle seals are leaking?

 

I don't think so. Don't see any moisture under the truck. It looks nearly new. Only 60k miles, no salt.

 

What about wheel speed vs driveshaft speed?

 

Wouldn't they be the same?

 

No

 

I realize they're not the same, but the final drive ratio remains constant. So how would the ratio between driveshaft speed and wheel speed change?

 

It wouldn’t.

If I hear the noise you’re talking about, it’s not constant. It happens x amount of times per second, increasing with speed.

If wheel speed, it would be at a slower rate than if driveshaft, which would be much more rapid at say, 30 mph.

Sorry, best I can do at the moment, still on first cup of coffee.

 

Yeah, I've pondered this as well. I can hear it going 65 and it seems like it sounds about the same--which is weird. You'd think the frequency would be much higher at higher speeds. In the vid I was only going about 25-30 mph.

Thanks for the help!

 

Then it’s not rotational / drive train related in any way I can think of.

 

Is there any vibration you can tell coming from the middle/ back of vehicle at speed?

 

nope

 

I think you and I have the same noise. My center support bearing just started to squeak. Starts around 20 mph. Gets worse the more I drive (as it gets hotter). I'm ordering one now.

 

I don't have a center support bearing.

 

Oh, reg cabs have a single piece driveline?

 

Yep

 

Apologies. And thanks for informing me of something I didnt know lol. Good luck!

 

I wish it were that simple. I'm thinking this might be expensive.

 

Can you put it on jacks and see if you can reproduce it with the drive wheels in the air?