Rear Differential Whine

[EddieC]

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?

 

[Doubeleive]

could be the pinion bearing but i would go back to the shop that did the work recently and find out

 

[Foggy]

sounds exactly like a bad ring gear (ring & pinion need replaced)

 

[EddieC]

The transmission shop, claiming to have lots of differential work under their belts, had said they fixed all that needed fixing when they changed the carrier bearings so I have reservations about throwing good money after bad. The work done didn't cost all that much but it's a PIA now.
Should I just have all the guts replaced somewhere else?

 

[George B]

Would they be willing to double check their work? Maybe they didn’t get the crush sleeve on the pinion all the way or something changed like it came loose.

 

[EddieC]

Would they be willing to double check their work? Maybe they didn’t get the crush sleeve on the pinion all the way or something changed like it came loose.

Not sure they even took it out being they only changed the carrier bearings which I am guessing are two bearings.
I did notice quite a bit of backlash before and after the service. I don't know if that could have been addressed but it wasn't if it could have been.

 

[jz57]

1) What model/year/mileage of your truck?

2) Did you get back all defective parts back from shop after rear differential job has been done? That can help us to dermine what parts were replaced.

3) How much did shop charge for the job? That can help us estimating how much job was done.

4) Based on your original symptom, the grinding noise usually comes from broken spider gear set. The repair should be more than replacing carrier bearings.

5) After repairing, the noise became whine, which is usually caused by ring and pinion gears backlash which should be within 5/1000 - 12/1000 inch. The job is including adjusting shim thickness between carrier and differential housing on both driver and passenger sides.

 

[EddieC]

1) What model/year/mileage of your truck?

2)Did you get back all defective parts back from shop after rear differential job has been done? That can help us to dermine what parts were replaced.

3) How much did shop charge for the job? That can help us estimating how much job was done.

4) Based on your original symptom, the grinding noise usually comes from broken spider gear set. The repair should be more than replacing carrier bearings.

5) After repairing, the noise became whine, which is usually caused by ring and pinion gears backlash which should be within 5/1000 - 12/1000 inch. The job is including adjusting shim thickness between carrier and differential housing on both driver and passenger sides.

1) 2008/100,000.
2) No parts returned but Invoice and verbal description stated only carrier bearings and axle seals were addressed.
3) $400, like I said "not too much".
4) I can't speak to that. It was a constant gear grind sound but otherwise drove around without physical symptoms other than the noise. I've broken a spider gear 55 years ago and the car wasn't moving after that bit of adolescent behavior.
5) It seemed quiet at first but now the whine is escalating with each drive during the past 2 weeks. It's been about 700 miles since the service.

 

[Doubeleive]

strange that they would do the wheel bearings, carrier bearings, and not address the pinion would have been real easy at that point now it's going to be $600 just for that

 

[jz57]

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.