Which Diff Fluid for 2017 Ram 1500 5.7L 4X4

[dh202]

Hi All, I'm new to the forum and looking for a little advice. I'm going to change the front and read differential oil on my 2017 Ram 1500 1500 Bighorn 5.7L 4X4. My owners manual says to use 75W-85 in the front and 75W-140 in the rear. I have seen a lot of articles that suggest using 75W-90 front and rear is better. I bought 75W-140 for the rear before I saw the articles about using 75W-90. Any thoughts on this?

Thanks!

 

[Burla]

Do what the book says... More heavy duty rear ends take the thinner 90 weight, your truck benefits from the 140 in the rear. The hd diffs are built to take the 90 weights, many of them, I'm not sure about ram hd, but whatever. 90 weight is known as universal, but their are applications that go away from that, and ram 1500's are one of them. I do run the 90 in the front, but either way is fine, just dont mess with rear diff.

 

[Jas34]

FWIW, I used Valvoline synthetic 75w 90 in the front and their synthetic 75w 140 in the rear of my 2017. The 75w 90 was readily available and I'm not sure, and didn't look for 75w 85. They may have changed the spec for the rear end to 75w 90 somewhere around 2017 but I went with what my owner's manual said to use.

 

[Black1500Ram]

+1 on valvoline syn in 75w90 & 75w140

Available at Walmart and their squeeze bags are nice you don’t need a pump.

Front diff is a 8mm hex (25 ft • lbs), rear diff plug is a 14mm hex (1 finger pull on a 3/8” ratchet until tight) - I dunno the actual spec.

 

[Jas34]

Yeah, the squeeze bag was the selling point for me. I hate having gear oil run down my arms.

 

[Nick@GotExhaust]

75w85 or 75w90 in the front & 75w140 for the rear. We offer Amsoil and Red Line for anyone interested.

 

[dh202]

Thank you all for the info!

 

[grizzstang]

You should find out what kind of rear diff you have.

If you have a limited slip you will need gear oil with friction modifier in it (not all of it does) or add a bottle of friction modifier after.

 

[Black1500Ram]

You should find out what kind of rear diff you have.

If you have a limited slip you will need gear oil with friction modifier in it (not all of it does) or add a bottle of friction modifier after.

Several of the major synthetic brands already have friction modifier in it.

 

[kdoublep]

I just did the rear at 67K with Amsoil severe gear 75w140. I did add a full 4 Oz bottle of mopar modifier even though Amsoil says it's already in there.

 

[Atcer2018]

+1 on the Valvoline choices. Squeeze bags, full synthetic, readily available, good price and it already has the friction modifier in it if yours requires it. I have a 2018 with the ZF rear. Doesn’t require friction modifier but using the modifier won’t hurt it.