Rear Differential Whine

[grbmds1]

We had a serious rear differential grinding noise all the time, on and off the throttle. Trans shop changed the carrier bearings a month ago and it seemed good or a while.
But after a couple weeks we're getting a loud gear whine noticible above 40 mph when lightly on the throttle. When coasting, the sound subsides but touch the throttle and it's immediately back so it seems loading the gears is the key. Popping it in neutral while coasting makes it silent.
Any ideas?

My 2015 Yukon xl is at the dealership right now for very similar issues. We get the whining noise when decelerating though mostly starting between 30 and 40mph. The noise goes away when popping it in to neutral. We also started noticing spinning of the rear tires when releasing the brakes from being stopped. It’s very frustrating, no error codes or warning messages.

 

[EddieC]

My 2015 Yukon xl is at the dealership right now for very similar issues. We get the whining noise when decelerating though mostly starting between 30 and 40mph. The noise goes away when popping it in to neutral. We also started noticing spinning of the rear tires when releasing the brakes from being stopped. It’s very frustrating, no error codes or warning messages.

You'd think differentials would be worked out by this time in the evolution of vehicles. Then again, I had a Jeep GC that had three rear ends in 40,000 miles before I gave up completely on any future Chrysler product.

 

[2006Tahoe2WD]

This thread seems like a good place to post my question. I have a slight whine 45-55mph. I can turn it on and off by a positive throttle or lifting. The noise goes away when there is no force (floating) I call it. I was thinking of checking the gear pattern and backlash with the diff. in the Tahoe. What are the thoughts on this? The carrier bearings were replaced not long ago.

 

[Geotrash]

This thread seems like a good place to post my question. I have a slight whine 45-55mph. I can turn it on and off by a positive throttle or lifting. The noise goes away when there is no force (floating) I call it. I was thinking of checking the gear pattern and backlash with the diff. in the Tahoe. What are the thoughts on this? The carrier bearings were replaced not long ago.

A slight whine is normal on these, but if it's getting louder I would suspect a pinion bearing. What year, and is it a 4WD or 2WD? Mileage? I'm asking because I assume that because you're posting on the '07-'14 section, your screen name no longer reflects your ride.

 

[2006Tahoe2WD]

I guess I posted in the wrong place by accident.
2006, 175k miles, 2 wheel drive, carrier bearings replaced ? 35k ago.
There is another thread going that I found where the guy used the paint to see what he could find. The mechanic said that the pinion bearings wear or shift. The whine is not very noticeable but I worry about things. Maybe fix something before the gear teeth are worn too far. Thanks.

 

[EddieC]

My carrier bearings were replaced by a trans shop that claimed to have hundreds of replacements under their belt.
After the bearing replacment (which were grumbling) I had a noticible whine. The bearing noise was loud so the whine may have been there before.

I had someone more experienced in 4wd and claimed to be knowledgeable in Chevy truck diffs rebuild it and he said that the trans shop had the backlash too tight.
The entire thing was rebuilt by the 4wd shop with new diff, gears, bearings and seals.
After proper break in, whine! Brought it back and backlash was changed a couple of times and all it did was move the whine to a different road speed point.
Bottom line to me is that some whine is normal or no one I've come across has a clue about the finer points of differential assembly.
I'm putting miles on and will see what debris ends up in there at a Spring fluid change.

 

[2006Tahoe2WD]

That's frustrating to be sure. I wonder what the pattern is using the yellow paint.

 

[EddieC]

That's frustrating to be sure. I wonder what the pattern is using the yellow paint.

In reference to mine, both shops had photos of the various setup patterns. They were happy but I can't say I have experience to know the finer points.