“ See your dealer” for advice on GM truck rear diff lubricant

Is that right ?
Geez - the 5.3L has 383 torque …
Yep. The Gen 5 version of the 5.3 with direct injection jumped the torque by over 40 lb ft, while the 6.0 had just normal fuel-injection. The 6.0 never did get direct injection. Chevy then went to the Gen 5 LT-8 with 6.6 liters with direct injection, getting more torque from both increased displacement and the direct injection.
 
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Here are the torque and horsepower curves for the first Gen 5 5.3 and the last Gen 4 6.0. The scales are different but the curves are very similar.


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Using some info from Car & Driver, the 6.6 gas engine replaced the 6.0 in 2020 and the transmission changed from a 6 speed 6L90 to the 10 “speed “Allison” in 2024. Edited from 2000 to 2020.
 
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Talking to a guy at the dealership (and no official position) - there is more in the OM from lawyers than engineers …
Blame that on an out of control legal system … and 45% for those “caring folks” in nice suits - and a gullible jury …
I’m going to put 75W90 Delvac 1 in the ‘22 Tahoe … still have to figure out the transfer case …
I assume they want a Dex VI in the x-fer case?
 
I understand Magna Powetrain is still the supplier and that they still use Dex VI, however many folks like to use another supplier.

Here is a chart of past transfer cases. The big dog for Auto ( Auto Trac) transfer cases was the MP 3024 but the new one behind the Allison is the MP 3025.

I believe you can get the Auto Trac or the non Auto Trac with electric selector but there no longer a stick selector.

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Should we call the 10L1000 an Allison? No way Allison would sell & warranty this unit in medium duty trucks.
I’m suggesting they went to that - I’m aware of what models are in what years with a friend having gone to the new 2500 to get the Allison which has the icon on his hood … Did not want DMax …
(He tows Jeeps+ATV’s in the mountains) …

 
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Being I have some it should be fine - the 10 speed runs ULV and sure don’t want that … I like my Jeep takes ATF+4 which is a bit thicker and high standards as well …
Not that you'd want to or should, but I'd imagine most non "automatic/AutoTrak" transfer cases could probably run anything ATF like, ATF+4, Dex VI, Dex 3, Mercon, etc. I use ATF+4 in my older 90s-mid 2000s Polaris transmissions which are kinda a snowmobile clutch driven two-speed transfer case.
 
Not that you'd want to or should, but I'd imagine most non "automatic/AutoTrak" transfer cases could probably run anything ATF like, ATF+4, Dex VI, Dex 3, Mercon, etc. I use ATF+4 in my older 90s-mid 2000s Polaris transmissions which are kinda a snowmobile clutch driven two-speed transfer case.
Yeah, I put the new Valvoline multi extended in my 6L80e and actually need a bit more for when I change the filter in cooler weather … probably better than Dex …
 
My new to me 2019 Silverado has the AAM RPO SU7 as well. Mine is an open diff and I changed it last week and used Mobil Delvac1 75w90. Now I’m second guessing my choice. Do I have any reason to be concerned?:oops:
Do you need to be concerned that you used a fluid that far exceeds the capabilities of the OEM recommendation? No. You’re good for at least 50-75k!
 
Talking to a guy at the dealership (and no official position) - there is more in the OM from lawyers than engineers …
Blame that on an out of control legal system … and 45% for those “caring folks” in nice suits - and a gullible jury …
I’m going to put 75W90 Delvac 1 in the ‘22 Tahoe … still have to figure out the transfer case …
0w-20 in my T-case. will probably go back to 5w-30 in a few months when i change it.
 
i have HPL diff life 75w-110 in my GM 10.5” with Yukon 4.88’s in it. HPL diff life 75w-90 for the front diff if i can ever get around to installing a heli-coil on the drain plug thanks to houston driveline.
 
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