Amsoil Severe Gear oil - Add modifier or not?

[Blackshirts]

1500 Bighorn 4x4. Anti-Spin differential.

Amsoil Severe Gear oil says it has Friction modifier in it.

I am doing a lot of reading and see conflicting recommendations. Some say adding modifier is not needed, others say modifier is needed.

Thoughts??

Thanks

 

[UnloosedChewtoy]

I'm a big Amsoil guy. Use their motor oil and, if not LSDs, their gear oil. But their gear oil seems to leave the modifier bits vague-ish for our trucks. Seemed to be just fine in the rear end LSD of a 2019 Challenger we used to own, but the Rams' rear ends seem to be a bit pickier.

I've used it on two Ram limited slips, a 2014 and a 2020. Both required me to add at least half of the required friction modifier (Mopar), otherwise the rear would chatter in turns.

I drained the factory rear end stuff and replaced it with Ravenol gear oil in my 2025 Tungsten (also has LSD) earlier this week. Stuff states it already has modifier in it, and it is true. Drove it a handful of times since then, no rear end chatter, all is well.

Why Ravenol: I was already ordering the transfer case fluid from them (specifically designed for the BW44 series t-cases), and thought I'd give them a try. May not be quite as good as Amsoil, generally speaking, but definitely a step (or more) above the standard Mopar stuff, and not having to mess with friction modifier measurements was worth it to me.

 

[Cbty2050]

Why Ravenol: I was already ordering the transfer case fluid from them (specifically designed for the BW44 series t-cases), and thought I'd give them a try. May not be quite as good as Amsoil, generally speaking, but definitely a step (or more) above the standard Mopar stuff, and not having to mess with friction modifier measurements was worth it to me.

Ravenol and Pennzoil/shell manufacture/supply Stellantis with their gear oil/4×4 fluids.

 

[UnloosedChewtoy]

Ravenol and Pennzoil/shell manufacture/supply Stellantis with their gear oil/4×4 fluids.

I'll take your word for it, but Ravenol's fluids always rank higher than the OEM stuff in testing and use, so I'm guessing there is a "bulk cheap Ravenol" vs "high-end Ravenol" at least, just like there is with Pennzoil/Shell.

 

[Mr.Grid]

For diff fluid replacement I used Mobil 1 75w140 (no additive) with the 3.92 limited slip in my 2011 Ram and didn’t notice any difference. Plan on doing same in the 2022 Ram when 100k arrives if I still have this one.

I use 75w90 Severe Gear in the drag car 9” that has a spool w/ 5.14.

 

[zlman]

I put Amsoil Severe Gear oil in my last truck, didn't add any modifier and it was fine for the remaining 20k miles I owned it. Doesn't Amsoil state the modifier is in the mix?

 

[RHO]

1500 Bighorn 4x4. Anti-Spin differential.

Amsoil Severe Gear oil says it has Friction modifier in it.

I am doing a lot of reading and see conflicting recommendations. Some say adding modifier is not needed, others say modifier is needed.

Thoughts??

Thanks

I had a jeep with the quadra drive , other gear oil brands would say "they already had modifier " but I would read farther and it would say does not meet Chrysler specs for jeep quadra drive , so just would pick up a couple of bottles from the dealer or order on line. I do that also with my 5th gen.