Metallic Grinding From Rear End: Speed Sensitive

[DocMike]

Getting a metallic grinding. It is speed sensitive like the post states.
Sounds like light metal on metal contact. It's loud with top and doors off.

2020 JT. Regear to 4.88 back in August 2021. Diff fluid good. Just changed at 2 months ago. no metallic shavings.
Tested wheel bearings. Drove at 40 and sound was consistent when moving left and right.
Sound happens when driving. Neutral, 4 lo, 4 hi and with traction control on or off.

Raised Jeep and spun wheels. Jeep only gave a slight amount of rubbing sound but not loud on the passenger side. Standard noise from gears.


Pulled wheel off. No rocks in between dust shield and rotor. Spun again slight rubbing from brake pad.
No signs of scoring on rotor.


Discovered busted retainer clip.
See pics. pulled a rather large chunk out of the pad thinking that is the culprit.
Going to try to source a new clip tomorrow.
Noise still persistent.
Did I diagnose it or any other ideas? It's loud when driving and quiet when elevated.

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[DocMike]

Plan for tomorrow is to get that replacement clip and then look into a potentially bad wheel bearing. Not sure where else to head at this point.

 

[DocMike]

Ok, this should be moved to axles and gearing. Mods please move!
I took it to Perkins Jeep as I could not find the clips.
Their tech suggested it was brake retention clips.
However they are on backorder. So his solution was to wait, replace the clips and see if the noise went away.
I was told I could drive on the noise to Tennessee.

Not feeling that I called a few brake shops. Sure enough. They had the parts. Cost me like $60 to get it fixed.

Done.

Noise still there. Tech said it sounds like the diff to him.
Call the off road shop that did my regear. He's slammed, but super cool about squeezing me in.

He drives it. Agrees it's awful. Noticed rubbing on the cage for the drive shaft near the rear pinion.
Sees things are loose.
Inspects the diffs because he did the work. Still great. Stuff.

Pinion bearing is going is what he reports. It's why the drive shaft is rubbing.

I ask about that. Seems odd on a truck with 29k. He said the only time he sees them go is when non mopar gear lube is used. Told me that the non mopar stuff eats the bearing housing. He's confused as he put Mopar lube in. it's in his notes.

I flushed with Lucas 3 months ago.

Anyone heard about this?


Now I am waiting on parts to hopefully arrive today so he can fix and I can leave tomorrow.

 

[DocMike]

Noise gone. Case closed. Pinion bearing.

 

[ShadowsPapa]

Noise gone. Case closed. Pinion bearing.

Sounds like an ok guy on differentials.
Glad it's FIXED and quiet.

 

[DocMike]

I do not pay for much, I like to do my own crap. But he will be doing my lockers.
And it's weird what I thought was tire noise with some metallic rubbing was all that bearing.

Sounds like an ok guy on differentials.
Glad it's FIXED and quiet.

 

[ShadowsPapa]

I do not pay for much, I like to do my own crap. But he will be doing my lockers.
And it's weird what I thought was tire noise with some metallic rubbing was all that bearing.

And yet these bearings made no noise at all........ I only found them because I decided to check pinion bearings when replacing a pinion seal. To get the pinion out to replace the bearings, you have to remove the carrier -

Oh, but wait, there's more!
I found one of the cups had been spinning in the housing and cut grooves in this shim -

And when using my hand to scoop out the rest of the lube still in the differential housing, that small piece fell out with the lube - that's about 1/4" off the end of the right axle. How the XXXX that could even happen we'll never know.

 

[DocMike]

Mystery for sure. It was loud. Truck is so quiet now. Even with 35s

And yet these bearings made no noise at all........ I only found them because I decided to check pinion bearings when replacing a pinion seal. To get the pinion out to replace the bearings, you have to remove the carrier -

Oh, but wait, there's more!
I found one of the cups had been spinning in the housing and cut grooves in this shim -

And when using my hand to scoop out the rest of the lube still in the differential housing, that small piece fell out with the lube - that's about 1/4" off the end of the right axle. How the XXXX that could even happen we'll never know.

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