Rear diff oil for 2017+

[Rickyd31]

I want to change my rear diff oil on my 2017 1500 ram. 3.92 lsd. C235

Owners manaul ( printed in 2016) said 75w140

Owners manual online said 75w90

Dodge checked with my vin and said 75w90


Who is right ? I bought both and i guess ill see the viscosity when i dump it. You can tell one is more liquidly than the other.

 

[David H]

Pretty sure most of us use the 140 in the rear and 90, or 85 up front. That's what I used earlier this year anyway.

 

[Daw14]

They changed the viscosity to gain a fraction of a fraction of mileage.
The 140 seems like it would be better for longevity ,and is what I would use if my truck was newer .
I have a 14 and it calls for the 140.

 

[David H]

Owners manaul ( printed in 2016) said 75w140

Also, I believe that 140 you have, MS-8985 requires a LS additive for the rear. MS-10111

The rear takes something like 3 qts. The mopar product is like $25 a qt. You might consider something like this instead plus it comes with the LS additive. Half the price and widely used here.

 

[Burla]

90 or 85 for the front, 140 for the rear.

 

[QwikKota]

The bags of Valvoline are so much easier to use.

 

[Bmags]

Also, I believe that 140 you have, MS-8985 requires a LS additive for the rear. MS-10111
View attachment 570270
The rear takes something like 3 qts. The mopar product is like $25 a qt. You might consider something like this instead plus it comes with the LS additive. Half the price and widely used here.
View attachment 570271

This is what I put in my truck and my brothers. 2019 Ram Classic with factory Anti-Spin.

 

[HEMIMANN]

It's the only half ton truck I ever saw spec'ing a 140 rear gear oil.

IDK if it's wishful thinking (a heavy duty wannabe) or they choose a chintzy axle set.

Hell, my heavy duty AAM with 11.5" dia. ring gear (! bigger than Ford Super Duty) calls for 75W-85 or 75W-90.

IDK, maybe the teeth are so big the load stress is low.

 

[TC]

^^^ because of this I chose to run Amsoil 75-110. 3.21 rear end seems to like it. No towing.

 

[RedSRT4Me]

I use this on my 2015. Already has limited slip additive included