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Differential oil

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Hello, after doing a bit of research I see that the oem differential lube oil is 75/85 however I see a lot of people running 75/90 . Does anyone having experience with this? Thanks.
 
75w-90 was the standard for a long time in the AAM axles. It's likely Ram went to 75w-85 for slightly better fuel economy, but it's going to be negligible.

I used 75w-90 when I changed my gear lube out.
 
I currently do not tow, do you think it’s an issue ? I bought amsoil 75/85 before I found that a lot of people use 75/90.
 
My duramax 11.5 lived a long life on 75w-90. My Ram 11.5 hasn't complained about 75w-140.

EDIT - the thickest oil the differential will ever see is the 75w at whatever cold temperatures it experiences. The thinnest it would see is the 85 hot, (summer towing hillclimbs) recommended by OEM. As such, going thicker on the hot side will always be bounded by these two extremes.
 
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First of all, let me thank everyone for the insight , experience and personal opinions. Very much appreciated, talked to Amsoil- every said was confirmed and was told 75/85 was created and released 2024 with limited slip specifications . Thank you so much.

I really do not like that Ram does not have drain locations on the differential. I have not found information for a front differential cover with a drain location, any thoughts?
 
Anyone anyone have personal experience with Revmax valve body for the 68RFE? Just looking for personal experience and opinions, thanks
 
2021Leveled said:
First of all, let me thank everyone for the insight , experience and personal opinions. Very much appreciated, talked to Amsoil- every said was confirmed and was told 75/85 was created and released 2024 with limited slip specifications . Thank you so much.

I really do not like that Ram does not have drain locations on the differential. I have not found information for a front differential cover with a drain location, any thoughts?
Click to expand...
Here is a pic of the front and rear cover I put on with drain holes.
FrtCover3500.jpgrearcover3500.jpg
www.aev-conversions.com

AEV Rear Differential Cover for 2010+ Ram HD

Equip your 2010+ Dodge Ram 2500/3500 with AEV's rear differential cover. Designed for maximum strength, this cover ensures top performance and longevity.
www.aev-conversions.com www.aev-conversions.com
 
The PML aluminum covers are currently on sale at a few places. Genos has them in the clearance section for the front and rear. Probably the cheapest way to get drain/fill plugs vs Banks. That said, I'm a big fan of pulling the cover, inspecting gears, and wiping down the interior surfaces with a shop towel.

The AEV covers are thick, cast iron, intended for off-road impacts. Not really a need that I personally anticipate.
 
johnmyster said:
My duramax 11.5 lived a long life on 75w-90. My Ram 11.5 hasn't complained about 75w-140.

EDIT - the thickest oil the differential will ever see is the 75w at whatever cold temperatures it experiences. The thinnest it would see is the 85 hot, (summer towing hillclimbs) recommended by OEM. As such, going thicker on the hot side will always be bounded by these two extremes.
Click to expand...
You have this backwards. The front number is the cold flow rating (75). The back number is the hot flow rating (85,90,140). The higher the number, the “thicker” the oil is. The advantage of a multigrade oil is that it is “thinner” in colder conditions and then “thickens” as it warms up to provide better protection.IMG_1479.jpeg
 
Will 9 qts get both the front and rear changed on my 2021 2500? TIA


Sent from me
 
mbarber84 said:
You have this backwards. The front number is the cold flow rating (75). The back number is the hot flow rating (85,90,140). The higher the number, the “thicker” the oil is. The advantage of a multigrade oil is that it is “thinner” in colder conditions and then “thickens” as it warms up to provide better protection.View attachment 84807
Click to expand...
Wait, you actually think oil thickens as temperature increases? Please show your source. Don't let the bigger number fool you. The two different numbers are on two different scales, at two different temperatures. FYI, your chart indicates straight grades.

For example 5w-30. It's "same" as a cold 5w when cold, and same as a hot SAE 30 when hot.

Here's my data. Please go back to post #5 and realize what I said was 100% correct.

1757336499184.png
 
johnmyster said:
Wait, you actually think oil thickens as temperature increases? Please show your source. Don't let the bigger number fool you. The two different numbers are on two different scales, at two different temperatures. FYI, your chart indicates straight grades.

For example 5w-30. It's "same" as a cold 5w when cold, and same as a hot SAE 30 when hot.

Here's my data. Please go back to post #5 and realize what I said was 100% correct.

View attachment 89459
Click to expand...
No, I don’t.
That’s why the words “thicker” and “thinner” are in quotations. Thicker and thinner being relative terms.
 
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