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Joining the rear diff club

94cruiser

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I don’t trust the first dealer.

I had to get the tech on a test drive with me to point out front LCA and I had to break hard to replicate the noise at each breaking. Harder than I would break normally.

the tech gave me veal about driving hard. As if that’s outside the car spec.
 

Rhetoric

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These dealer stories just suck. Do other models of cars with this diff have the same seal issue? I wonder if the Focus RS guys see what we are seeing. Maybe they just blow up the diff to soon to find out? ;)

It also seems absurd to me that a seal is not "serviceable". Come on. However, if even GKN can't get the seals in right I don't have much faith in a dealer mechanic (or myself) getting them in any better.
 

jdoodle

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Texas
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2018 regal tourx
Just received a call from my service advisor. They will replace the rear diff. It's in stock in Lansing and expect to have it here (Texas) in a couple of days and I should be good to go by mid next week. Fingers crossed and can't wait to get out of the Malibu loaner.
 

jdoodle

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Texas
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2018 regal tourx
These dealer stories just suck. Do other models of cars with this diff have the same seal issue? I wonder if the Focus RS guys see what we are seeing. Maybe they just blow up the diff to soon to find out? ;)

It also seems absurd to me that a seal is not "serviceable". Come on. However, if even GKN can't get the seals in right I don't have much faith in a dealer mechanic (or myself) getting them in any better.
Rhetoric, I'm guessing it's not a matter of the seal being good or bad or installed incorrectly, I'm thinking it's an assembly problem that the shaft is not running true or aligned correctly causing the seal to fail. Just conjecture on my part.
______________________________
 

Rhetoric

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Rhetoric, I'm guessing it's not a matter of the seal being good or bad or installed incorrectly, I'm thinking it's an assembly problem that the shaft is not running true or aligned correctly causing the seal to fail. Just conjecture on my part.
Add it to the great mysteries of a super low production unicorn wagon.
 

Jmlo96

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19 Regal TourX Essence
Just in case anyone is wondering, in addition to the AWD 2018+ Regals, the Ford Focus RS, Lincoln Continental and MKZ, Cadillac XT5 and XT6, Buick LaCrosse and Envision, GM Acadia, Range Rover Evoque and Land Rover Discovery Sport all use the same GKN Twinster rear differential. If seal failures are prevalent, it will be seen in all those models.
 

94cruiser

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Not exactly.
While they may have the same dif, the driveshaft lenght/model/angle and install process may be different per application.
(but still good info to have)
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ChibiBlackSheep

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Southeast, PA
Buick Ownership
Regal TourX Essence | Moon Blue Metallic
The differential other than axle seals is not serviceable based on the diagram below.
Looking at that URL the seals say:

  • SKU:23206451
  • Positions:Right
  • Other Names:Axle Seals, Seal
  • Description:
    Awd, without positraction. Equinox, Terrain. Envision. Right. With positract twin clutch.
  • Condition:New
  • Replaces:23206450
Our car isn't listed in the description, so while it might be a similar assembly, maybe different seal?
 

MelsRegal

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Regal GS 2017
Looking at that URL the seals say:

  • SKU:23206451
  • Positions:Right
  • Other Names:Axle Seals, Seal
  • Description:
    Awd, without positraction. Equinox, Terrain. Envision. Right. With positract twin clutch.
  • Condition:New
  • Replaces:23206450
Our car isn't listed in the description, so while it might be a similar assembly, maybe different seal?
Yes, it's the axle seal not the pinion seal which is not listed as a serviceable item. You can look up your specific year and model and check for your self.
 

94cruiser

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The one going to the driveshaft is the pinion seal, right?

Where does it say it's not serviceable item?
 

agaric

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2017 Regal GS AWD Crimson Red Tint Coat
There is no listing for the pinion seal.
Only the axle seals, item #4 are shown.
The description is very confusing when it mentions without posi and with posi and then left and right separately
like the parts are different.
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MelsRegal

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Maybe the dealer techs have access to different part number list?
In more likelyhood the pinion nut cannot be reinstalled without losing the correct pinion preload torque thus turning a seal issue into a pinion/ring gear issue. On historic rear wheel drive seal replacements, the nut had to be marked and then the number of turns counted to remove it from the pinion gear shaft. Then upon reinstalling it, the number of turns had to be the same and the position had to be the same, some manufacturers may add an additional fraction of a turn. The manufacturer of these new differentials may want them back untouched by dealer technicians even if it requires complete replacement. Once they are no longer under warranty the aftermarket may have to provide a seal and a reliable replacement procedure.
 
Last edited:

Human

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Buick Ownership
Present: 2013 Lacrosse hybrid. Past: 1984 Century Custom (1992-96); 1977 Skylark coupe (1983-88).
they had no problem with doing buick warranty work.
They already fixed my horn under warranty.

maybe yours just doesn't want to do the work.
That is a distinct possibility. Franchised dealers are independently owned and operated and have a certain amount of latitude when it comes to the work they are willing to do and it may come down to what other GM dealers are nearby. If say a Buick and a Chevy dealership are in close proximity, they may have a gentleman's agreement not to try to poach each other's customers. One thing's for sure; the folks at Amsbury recognize that by treating you right, they are taking the opportunity to create a good impression and possibly make you their customer down the road.
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Pacer69

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KC
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TourX
Just in case anyone is wondering, in addition to the AWD 2018+ Regals, the Ford Focus RS, Lincoln Continental and MKZ, Cadillac XT5 and XT6, Buick LaCrosse and Envision, GM Acadia, Range Rover Evoque and Land Rover Discovery Sport all use the same GKN Twinster rear differential. If seal failures are prevalent, it will be seen in all those models.

I did a quick google on Ford Focus RS differential issues, they have these same twinster problems listed going back at least as early as 2014. I'd think the mfr would've revised/fixed the issues by the '18 models...I sure hope GM did not saddle us with trouble on this. I can see it getting fixed under warranty, then you're out of warranty and stuck with the bill on a defective part like these Ford owners. Hopefully the Focus was the beta group (which ain't cool either) but maybe the issues we're seeing here are not widespread. My question is, does anyone with similar experience see a widespread issue here, or is it just us because we're on this board and share info? Open to any thoughts...seems like if it's indeed widespread catastrophic failures, only to be repeated...that it should warrant an unlimited lifetime warranty, or at least 100k miles per failure (assuming proper maintenance), with rollover and owner-transfer coverage.
 

Wlepse

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2018 Regal TourX Essence
Even if they acknowledge the defect they aren't likely to extend the warranty past 100k. Repairs would only be covered based on remaining extended warranty or the dealers normal warranty which is usually around 12 months and 15k miles.
 

Pacer69

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Buick Ownership
TourX
Even if they acknowledge the defect they aren't likely to extend the warranty past 100k. Repairs would only be covered based on remaining extended warranty or the dealers normal warranty which is usually around 12 months and 15k miles.
Yeah I can see that...sounds like it falls into the department of what I'd like to see, and even what seems fair ...vs reality...are different things. But I'd assume the parts are covered up through our standard warranty of 4 years/50k miles, at least on my '18. To me, a part that has in other vehicles shown itself to be defective, and which is a costly repair that demands repeating every 20-40k miles... should not be considered a consumable like brakes. Deserves extended warranty, at least to 100k if not 150k, just my opinion.

Acura had an a/c compressor issue in my '07 RDX, and extended the warranty for that part to 100k. I never had the issue, but it was good to know they did the right thing.
 

Wlepse

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I don't disagree....I think original coverage is to 70K since it is part of the powertrain but getting 100k would be nice. I did notice today they extended the warranty on the accelerator to 153K...that would be nice on the diff too.
 
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