Rear Differential Oil

[BobH2020]

I have a 2020 Ram 1500 Longhorn Limited. The build sheet says I have a 3.21 rear end. There's no mention of it being a Limited Slip Differential. Would there be any issues if the gear oil has a friction modifier? Also, looking to see what brand people have had the best luck with. Thanks in advance.

 

[fitteenhundred]

I like Valvoline in the flexfill containers. No problem with the fiction modifer.

 

[Wild one]

I like Valvoline in the flexfill containers. No problem with the fiction modifer.
View attachment 542460

Hopefully you realize your 2012 calls for 75-140.

 

[fitteenhundred]

Yes. In the rear. Thanks

 

[Burla]

Many years ago the industry decided that there was no "harm" by having friction modifier in an open diff, so bottom line all gear oils are made with modifier now. You have to go full boutique to find a gear oil without modifier, and that is more for ancient manual gear boxes. So to answer your question, you wont have issues with modified gear oil which is any "multi purpose" gear fluids. Amsoil ss and now Valvoline have great popularity and success mostly because of the bags, if you don't get these you will need a pump like slippery Pete. Unless you tow heavy or race, just use whatever one of those sooths your fancy.

 

[joesstripclub]

Many years ago the industry decided that there was no "harm" by having friction modifier in an open diff, so bottom line all gear oils are made with modifier now. You have to go full boutique to find a gear oil without modifier, and that is more for ancient manual gear boxes. So to answer your question, you wont have issues with modified gear oil which is any "multi purpose" gear fluids. Amsoil ss and now Valvoline have great popularity and success mostly because of the bags, if you don't get these you will need a pump like slippery Pete. Unless you tow heavy or race, just use whatever one of those sooths your fancy.

Yep I have a wavetrac installed in my 350Z and it specifically says not to use friction modifier. Mobil Delvac is the most cost effective I have found to purchase. I think the rear on my Ram can use the same fluid.

 

[HEMIMANN]

Many years ago the industry decided that there was no "harm" by having friction modifier in an open diff, so bottom line all gear oils are made with modifier now. You have to go full boutique to find a gear oil without modifier, and that is more for ancient manual gear boxes. So to answer your question, you wont have issues with modified gear oil which is any "multi purpose" gear fluids. Amsoil ss and now Valvoline have great popularity and success mostly because of the bags, if you don't get these you will need a pump like slippery Pete. Unless you tow heavy or race, just use whatever one of those sooths your fancy.

Except for Mobil Delvac 1 Gear Oil (I confirmed with Mobil) and Red Line NLS Gear Oil.

The exception is to reduce cost of the additive, I'm sure some decided the little amount of additive used cost more to not carry for those axles without LS - i.e., more axles are using LS these days.

That said, the few of us with AAM TracLite Torsen all gear mechanical locking differentials benefit from no LS additive, as it slows down lockup speed. How much I don't know. I just read a technical paper about it, is how I know.