ramacker

2016 JKUR automatic, makes a grinding sound when I let off on the gas. Anyone have any ideas on what this could be?
appreciate any help I can get.

Sixty4x4

Any oil leaking from the pinion seal? Could be driveshaft rzeppa joint?? Check under the boot to see if that is dry.

Mr.T

Here's what I would do: First check both ends of the drive shaft for play. Second, remove the differential cover and check the gears, gear mesh, and look closely at the oil as well.

resharp001

yikes. I'm thinking that is sounding more internal than DS related. Time to drain, remove the cover, and get a look at what's going on inside. Right around 14sec in you start to hear things start to kick in under load which makes me start to think bad pinion bearing maybe, which would make sense to lead to gear chatter as you let off the gas. At least that is my thought after listening a couple times. Has that jeep been regeared?

ramacker

Thanks for the quick replies.
The pinion is not leaking. I changed the rear wheel bearings, removed the carrier no play in the pinion that I could see, the oil looked good there were no metal chips gears

rear dif
looked good. The only thing I saw that looked a miss was wearing on half of the passenger side rear axle not all the way around it. It has not been re geared. The driveshaft doesn't have any play, rzeppa joint is not slinging grease and has no play.

rear passenger side axle.

Mr.T

More checks: Put a dial test indicator on the ring gear and measure the play between ring & pinion. Check it with the indicator at several teeth, evenly spaced. It could be that the carrier didn't go back in correctly (crud under a bearing race for example) and the old wear pattern is not the same as the old, gear play not even, etc. Blue the gears (marking compound) and check both the drive, and especially the coast side (since that's the side with pressure when the noise occurs). Here's a study guide that might help: https://www.freeasestudyguides.com/r...-patterns.html

Maybe I've misunderstood the sequence of events; Did the noise problem happen shortly after replacing wheel bearings, or removing the carrier, or after both were done together, or something else?

ramacker

Wheel bearings and carrier removal were done troubleshooting the noise. I had towed a pop up tent a few times prior to noticing the noise.

ramacker

Ended up being the pinion bearing.
Thx for all the help ​​​​​​​

ChadHubbard

I just want to thank you for posting the resolution to your issue. I wish that everyone who asks for help would take the time to post the resolution to their issue after asking for help. It would be helpful to share the fix, not just the issues or symptons.

Thank you!

resharp001

Glad you got it figured out. ​​​​​​​