17 JKU Rubicon with New Revolution 4.56 gear change. Reputable shop installed. First drive slight whining sound. Will it go away during break in? good bad or ugly? Advice Please..

 

Lot of times whining from diff is a pinion bearing. Not saying that is what it is, but that is the first thing my mind goes to. There's nothing wrong with going back and asking them to have a listen.

 

Those revolution gear sets do not need break in. If the diff is making noise take it back to the shop that did the work. I would ask if they hear or heard any noise?

 

Drove it again this morning. Sound appears to only be heard when slowing down. Faint sound… I do have new Nitto Ridge Grapplers too but they were installed a couple of weeks ago and I didn’t notice it. I have a 500 mile service coming up. Can it wait?

also why do the Revolutions not need the same break in process?

 

They are made with a special coating that allows them to be driven regularly without a break in period of different speeds to maintain. gear noise on coast tends to be pinion set too shallow. Might pull driveshaft and check the pinion nut torques to ensure its still tight. every now and then the crush sleeve will fail at installation and not sustain torque on the pinion shaft.

 

Its coming back apart.