Rear Differential Whine

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91RS

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If everything was done correctly, then it's either pinion bearing(s) or the ring and pinion gears themselves. This is why I'm hoping buying a used differential for mine is the way to go to save a lot of hassle replacing everything.
 
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EddieC

EddieC

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The price of $400 to replace carrier bearings is very good!

Here could be the ticket:

The issue is isolatd to carrier bearings area: adjusting shim to meet backlash or carrier bearing clamp bolt torque to meet GM specification (55-60 Ft.Lb).

Perhaps the price was too good to do extra job (backlash/torque) for you.
The thing is I didn't limit the job and that was not the original ballpark estimate for all bearings which was double.
I was prepared to replace everything and he knew it but when I picked it up he said that all they needed to do was the carrier bearings.

So would it be too late to make the adjustment or better to just write it off and have someone else make it all fresh?
 
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EddieC

EddieC

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If everything was done correctly, then it's either pinion bearing(s) or the ring and pinion gears themselves. This is why I'm hoping buying a used differential for mine is the way to go to save a lot of hassle replacing everything.
I priced that out and around here it was running $1800 and up plus shipping and installation for a minimum of 150,000 mile unit.
I had another quote for $1700 for complete rebuild with all new parts whether it needed them or not but the scheduling was not good at thew time.
 

bigdog9191999

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i had a situation where the rear cover rusted and slowly leaked the gear oil out so i ran it low pulling a trailer for about 150 miles loaded, then another 150 unloaded before i noticed, it was a cold winter day and that probably saved a little, but there was very very little metallic when i cleaned it out to change the cover so i ran it. it makes noise almost identically as described whine when on the throttle lightly and quite when coast. the wear pattern could be seen a little more pronounced than average but otherwise looked good, as i can deal with the whine we just cleaned it up an treated it like normal and i am just aware that it will make a little noise, basically forever. the only way to fix my particular issue would be ring and pinion ( which we attempted when we swapped the axle from one truck to another, but there was enough difference that we decided that it wasnt going to be worth the effort to make it correct and wanted the truck drivable quicker, being it was more "comfort" issue than a reliability issue.
 
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EddieC

EddieC

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Bigdog,
Thanks for that input but unfortunately our whine is distractingly loud and those things bother me just not knowing if it will leave either of us stranded somewhere. I actually liked my Muncie rockcrusher whine this is a different situation.
 
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EddieC

EddieC

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The other two shops on my list are booked out for more than a month so I guess I need to give the original shop a chance to take a look at it now that there is the noise that shows a shortcoming.
 

91RS

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I priced that out and around here it was running $1800 and up plus shipping and installation for a minimum of 150,000 mile unit.
I had another quote for $1700 for complete rebuild with all new parts whether it needed them or not but the scheduling was not good at thew time.

I’m not sure where you’re looking but I just had a 96k mile unit from a 2012 delivered for $520. They had a bunch cheaper than that one. They had one with 130k for $280 with damaged backing plates but I wasn’t looking to take mine apart to swap them.
 
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EddieC

EddieC

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I’m not sure where you’re looking but I just had a 96k mile unit from a 2012 delivered for $520. They had a bunch cheaper than that one. They had one with 130k for $280 with damaged backing plates but I wasn’t looking to take mine apart to swap them.
Not here. The shop that does other heavy repairs for me did a search on his system and many units came up at the price I noted and above) and none were even in our state. Maybe I should note it's a Z71 with a locker so maybe the combo makes them harder to come by. Scrap yards are becoming scarce around here, I presume because of environmental liabilities.

I remember in high school we had a great junkyard where $50 a day let us carry out everything we wanted. One trip yielded a hood, radio, bell housing and tranny to fit my '56 Chevy. Certainly better days.
 
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EddieC

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So the saga lives on.
It went back to the original shop to get checked. The whine was acknowledged, the gear pattern checked and deemed good. Slight wear on the gears was noticed. Ruled out pinion bearing issue because the noise is gone if the truck is shifted into neutral while rolling. The whine is primarily there when there is force on the gears, most noticeable with light throttle and it gradually curtails when lifting off throttle and as noted, silent in neutral.
The proposal was to replace the gears by process of elimination.
I don't think I mentioned that synthetic lube (per GM recommendations) was not used in the work but I don't know if that is critical.

Perhaps the whole thing should be torn down by a different shop. I have a line on a 4x4 shop and on an axle specialist.

Any more thoughts?
 

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