Does extra differential fluid cause issues?

[Z45]

35 minutes ago, newdude said:

 

 

Really...I'm actually surprised they didn't make that sooner given many light duty truck OEMs have been using it for some time now.  

They been busy expanding into the industrial manf and a grease manf .

https://blog.amsoilindustrial.com/2023/05/08/amsoil-inc-acquires-benz-oil-expanding-amsoil-industrial-business-unit/

https://blog.amsoil.com/amsoil-inc-acquires-aerospace-lubricants-with-strategy-for-growth/

[customboss]

1 hour ago, newdude said:

 

 

Really...I'm actually surprised they didn't make that sooner given many light duty truck OEMs have been using it for some time now.  

Market was small. 

[customboss]

55 minutes ago, Z45 said:

They been busy expanding into the industrial manf and a grease manf .

https://blog.amsoilindustrial.com/2023/05/08/amsoil-inc-acquires-benz-oil-expanding-amsoil-industrial-business-unit/

https://blog.amsoil.com/amsoil-inc-acquires-aerospace-lubricants-with-strategy-for-growth/

Our Land owners  association is using all their products in our large off road fleet via the commercial account and that aircraft quality grease from the former Ali-Syn is awesome. We buy drums of it. Nick really takes care of us. 

[newdude]

9 minutes ago, customboss said:

Market was small. 

 

 

A lot of GM 1500's produced since 2014 that have used 75w85...not exactly "small".

[customboss]

3 minutes ago, newdude said:

 

 

A lot of GM 1500's produced since 2014 that have used 75w85...not exactly "small".

Small for an aftermarket company who markets against big oil stake holders that control market. Another cogent point , GM pays shite for assembly and OEM lubes. They nearly bankrupted FUCHS and why they don’t produce for GM anymore. 
Retail lubes sales is a joke because most DIY are cheap and onesies twosies have nil profitability. Why Amsoil in late 60’s backed off attempting traditional retail sales. 

[Z45]

29 minutes ago, newdude said:

 

 

A lot of GM 1500's produced since 2014 that have used 75w85...not exactly "small".

Actually GM released new gear oil specifications for the late 2020 and 2021 model year pickups that now call for DEXRON Low Viscosity 75W-85 gear oil.

 

Squeeze another 0.1 mpg improvement for CAFE

Edited October 4, 2024 by Z45

[newdude]

15 minutes ago, Z45 said:

Actually GM released new gear oil specifications for the late 2020 and 2021 model year pickups that now call for DEXRON Low Viscosity 75W-85 gear oil.

 

Squeeze another 0.1 mpg improvement for CAFE

 

 

Both fluids are a 75w85 GL5 though.  19300457 in the AAM axles since 2014 to current, and 19368514 Dexron 75w85 for the GM axles starting 2019 T1 trucks.  

 

19300457 (10-4091) is 75w85 "High Efficiency", GL5 "synthetic hypoid gear lubricant made from Group III base stocks."  

 

19368514 (10-4122) is the Dexron LV Gear Oil.  It is also a GL5 lubricant, same 75w85 weight.  Oh, and its "vanilla" scented, not grape.  

 

 

What is sounds and seems like to me, is GM made their own "spec" for their "own in house GM axles" that they make.  That's all it seems like it is to me.  Anything for licensing purposes aka $$$$$$$, unless someone can prove otherwise out there with oil sample testing that there is a legit big difference between the two. 

Edited October 4, 2024 by newdude

[Interleukin6]

On 10/3/2024 at 11:58 AM, redwngr said:

 

How long was it stationary before checking? 

 

 

 

I checked it right after the fluid in and on the following day after my truck was parked on the drive way for more than 12 hours.

[Z45]

I just looked at the vehicle build for my 2024 Sierra built 7/20/24 in Medico, has the AAM axles SU4 and SU7.

 

The main difference between GL-4 and GL-5 gear oils is in the level of extreme-pressure (EP) additives.

• GL-4 gear oils are typically recommended for spur and helical gears found in manual transmissions and transaxles operating under moderate speeds and loads.
• GL-5 gear oils are typically recommended for hypoid gears in automotive axles operating under high-speed, high-load conditions.

[Interleukin6]

Let me ask another questions. This was first time for me to change the different fluid in my life. My GM one has a paper-like gasket already stuck on the mating surface of the diff. I used a razor blade to take it off, making some mild scratches on the surface. I read later these scratches would cause leaks eventually… then I got scared…. So far nothing has been dripping for 3 days. I see many are using a flat head screwdriver, razor blade, or metal scraper to take off the stuck gasket but some say that only plastic one should be used because plastic does not scratch metal… if it starts leaking, a RTV sealant will be the one rather than OEM gasket? Sorry for multiple questions. What are the pros and cons  of gasket vs RTV sealant? Thanks.

Edited October 4, 2024 by Interleukin6

[Interleukin6]

11 minutes ago, Z45 said:

I just looked at the vehicle build for my 2024 Sierra built 7/20/24 in Medico, has the AAM axles SU4 and SU7.

 

The main difference between GL-4 and GL-5 gear oils is in the level of extreme-pressure (EP) additives.

• GL-4 gear oils are typically recommended for spur and helical gears found in manual transmissions and transaxles operating under moderate speeds and loads.
• GL-5 gear oils are typically recommended for hypoid gears in automotive axles operating under high-speed, high-load conditions.

Mine is SU4 & SU8. Looks like the gasket of AAM rear differential (SU7) seems to be a rubber, easy to be removed, and reusable. GM one (part# 84412728) is NOT!!!!!!

[newdude]

28 minutes ago, Z45 said:

I just looked at the vehicle build for my 2024 Sierra built 7/20/24 in Medico, has the AAM axles SU4 and SU7.

 

The main difference between GL-4 and GL-5 gear oils is in the level of extreme-pressure (EP) additives.

• GL-4 gear oils are typically recommended for spur and helical gears found in manual transmissions and transaxles operating under moderate speeds and loads.
• GL-5 gear oils are typically recommended for hypoid gears in automotive axles operating under high-speed, high-load conditions.

 

 

Both oils are GL5.  

[txab]

RTV is fine. Many use it. Wonder what happened to the reusable gasket some of the trucks had?

[Interleukin6]

48 minutes ago, txab said:

RTV is fine. Many use it. Wonder what happened to the reusable gasket some of the trucks had?

Again, mine (GM diff gasket) was already torn and pretty badly stuck on the mating surface of the diff and cover when I took out the cover. It looked like a coated paper material. Of course, new gasket seemed same. When I changed the transmission fluid, the gasket was like a thick plastic/rubber. The gasket of AAM rear diff looks similar to the transmission gasket. Highly doubt GM one is reusable… Anyone who has SU8 plans rear diff fluid change, get a new gasket before taking off the cover!!!

Edited October 4, 2024 by Interleukin6

[newdude]

46 minutes ago, txab said:

RTV is fine. Many use it. Wonder what happened to the reusable gasket some of the trucks had?

 

 

AAM axles use the reusable cover gasket.  The GM axles are this one time paper.