So I recently replaced my rear differential gears because of a whining noise and shortly after a few days it went out on me. I previously fixed it upgraded to 373 gears and the whining noise came back with vengeance…. What could it be… be advised it is an Automatic 98 z28 camaro 5.7

 

Wrong forum for this topic - not “Advanced Tech”.

Moving to “Drivetrain”.

Did you do the install yourself, or was it done by an experienced shop?

 

It was done by a shop. Could it be that I have to break in the new gears and put a certain amount of miles on. Been driving it a few days now and still not subsiding

 

Go over the exact sequence of events. I think this is what you are indicating:

1 - "I previously fixed it upgraded to 373 gears and the whining noise came back with vengeance"… does that indicate you original factory gears were also whining?

2 - "I recently replaced my rear differential gears because of a whining noise and shortly after a few days it went out on me."... what does "went out on me" mean? Whining again? Some other failure?

That sounds like you have had a whining problem with three sets of gears.

Gears need to be "broken in", and the shop should have advised you on their recommended break in procedure. But "whining" is not normal for a new set of gears, if set up properly. It's not going to clear up. Did you go back to the shop and ask their advice? Were the most recent gears new, or used? Did they do a complete rebuild - carrier, head, and tail bearings, crush sleeve, shims, etc? Have the axle bearings ever been replaced? How many miles on the car? Do you know what brand gears they used?