[NSLRedHot]

I took my 2016 SS in to the local dealer to have the rear differential fluid replaced after taking it to the track (as recommended in the owner's manual). They replaced the fluid and the next day there was a horrible rubbing/groaning noise coming from the back end. I took it back to the dealer and they realized they put in the correct fluid, but did not add the lubricant additive that they were supposed to. They put in the additive and it helped a little. I took it back a third time and they swapped out the rear diff fluid with extra lubricant this time. It was better, but still not right. Still groaning and the rear tires chattering in tight turns. It is now at the dealer getting a whole new rear differential put in. Really? is it that hard to put the correct fluid in the first time? Worst of all, the service manager told me he will not refund the money that I originally paid to have the rear diff fluid exchanged!!! :

[zx9rmal]

It is my understanding that the current GM diff fluid now contains the additive. Sorry you're having the problem.

[JT58]

Another horror story to add to the list for me and why my cars do not go to the dealer unless is is something catastrophic or so obviously wrong. I do all of my own maintenance period.

[m4nat]

Originally Posted by NSLRedHot

I took my 2016 SS in to the local dealer to have the rear differential fluid replaced after taking it to the track (as recommended in the owner's manual). They replaced the fluid and the next day there was a horrible rubbing/groaning noise coming from the back end. I took it back to the dealer and they realized they put in the correct fluid, but did not add the lubricant additive that they were supposed to. They put in the additive and it helped a little. I took it back a third time and they swapped out the rear diff fluid with extra lubricant this time. It was better, but still not right. Still groaning and the rear tires chattering in tight turns. It is now at the dealer getting a whole new rear differential put in. Really? is it that hard to put the correct fluid in the first time? Worst of all, the service manager told me he will not refund the money that I originally paid to have the rear diff fluid exchanged!!! :

Wait when you say chattering from the rear tires what do you mean? Do you mean that when you turn left and right hard at low speeds the tires don't like it? I thought this was just because of me putting wider tires on the car (305s). At low speeds when I turn left or right hard, (like pulling out of my driveway and turning hard left or hard right) my rear tires don't turn super smooth, they sort of chirp. Is that something that could have to do with the rear differential?

[SSDanny]

Originally Posted by m4nat

Wait when you say chattering from the rear tires what do you mean? Do you mean that when you turn left and right hard at low speeds the tires don't like it? I thought this was just because of me putting wider tires on the car (305s). At low speeds when I turn left or right hard, (like pulling out of my driveway and turning hard left or hard right) my rear tires don't turn super smooth, they sort of chirp. Is that something that could have to do with the rear differential?

Maybe an alignment issue, not the width of the tires much.

[m4nat]

Originally Posted by SSDanny

Maybe an alignment issue, not the width of the tires much.

I think it is a tire issue, because when I had 275s I did not experience anything like this. Will be getting an alignment done soon, thanks man

[born-to-fish-]

Every muscle car I've owned with a Posi-trac differential had a slight REAR wheel chatter when turning sharp at low speed.

[CAM-FIFTY]

Ackermann steering chatter is different from what OP is describing.

[17txcamaross]

Originally Posted by m4nat

I think it is a tire issue, because when I had 275s I did not experience anything like this. Will be getting an alignment done soon, thanks man

Even just changing from 275 to 305 tires an alignment is needed.

I had my car aligned following lowering my car and put it in perfect spec. Two days later my wheels showed up. put them on and realigned. Alignment shop showed the car was slightly out of alignment.

[fastball]

Tell him to either refund your money or you'll give them all zeroes on the service survey you will receive in the mail. They take that stuff seriously.

And if he doesn't refund you, give them all zeroes.

[craigss50]

Since the correct fluid already has the lube added they put the wrong fluid in.

[wavsine]

Originally Posted by fastball

Tell him to either refund your money or you'll give them all zeroes on the service survey you will receive in the mail. They take that stuff seriously.

And if he doesn't refund you, give them all zeroes.

Isn't this covered by the powertrain warranty?

[Ruebernard]

And the dealer is making good by replacing the differential. I assume they are eating the cost...so why try and stiff them for the cost of the initial visit?

[S2K+1LE]

Dealers don't "eat the cost" of warranty work, the manufacturer reimburses them for time and materials. That's how they MAKE money.

The fact that they completely screwed up the service which caused multiple repeat visits, multiple days without the car, and customer frustration is *exactly why* they should be refunding the money spent for the fluid swap. Oh, and the fact that they obviously did it wrong and therefore shouldn't charge in the first place. That's pretty obvious to me, they wouldn't keep my money.