Mild Clicking on Deceleration

[8thTon]

When pulling to a stop I hear a mild click, which is obviously at driveshaft speed. It's not loud, and it never does it with any power applied, but if I'm out of the throttle I can hear it. Is this likely to be the pinion bearing or just wear on the gear faces?

 

[Uncle Gump]

Any kind of vibration in either loaded or coasting?

If you suspect rear end... I would pop the cover off and take a solid look around.

 

[8thTon]

Any kind of vibration in either loaded or coasting?

If you suspect rear end... I would pop the cover off and take a solid look around.

No, it's smooth and makes no vibrations or other rear-end-failing kinds of sounds. I topped off the fluid a few weeks ago - it was a pint or so low - and the fluid that was in there seemed pretty clean (I pulled some out just to see).

 

[Uncle Gump]

I just know most times with rear end issues there is a hum... whine... howl and also some sort of vibration. Not always... but...

Is this an open rear end or a trac lok?

 

[8thTon]

I just know most times with rear end issues there is a hum... whine... howl and also some sort of vibration. Not always... but...

Is this an open rear end or a trac lok?

Yeah, there's no whine or howl like what I'd expect, which is why I'm curious. With an offset hypoid gear the forces on the gears are rather different when the pinion is driving the ring gear vs. the other way around.

It's an open diff 8.8 with a 4.10 gear.

 

[sgtsandman]

U-joints going bad?

 

[8thTon]

U-joints going bad?

Oh, yeah, I forgot to mention that. U joints was my first guess too, but they feel fine. I jacked up the rear and spun the shaft - there was no play or slop, or anything that seemed wrong with them. Hardly a definitive test but I really don't think it's the U joints.

 

[85_Ranger4x4]

Best way to test u-joints is to remove each end from the truck and actually feel how things move.

If they don't have grease zerks... there is a good chance they are original.

 

[8thTon]

I have read that this type of noise (pinion speed, only on deceleration) can be a chip on defect on a face of a pinion tooth. However, I've noticed that the noise is simply not there when it's cold and only shows up after driving some distance. When the snow goes away enough to work in the driveway I'm going to pull the cover and see what's going on, and refill with thicker gear oil.

 

[cbxer55]

I run 75W-140 in all my Fords. My Lightning takes it, and I always have it in the grudge, so I sue it in everything, even my shaft driven motorcycle.

 

[Eddo Rogue]

Maybe its just your teeth?

 

[8thTon]

But I brush daily?

 

[Eddo Rogue]

But I brush daily?

Gotta floss too, thats where they get ya...