Differential/Transfer Case Fluids Debacle

[VOwens]

I have a 2017 Ram 1500 4x4 with a 235mm rear axle and limited slip and a 215mm front axle. At least that's what a VIN check on Mopar.com yielded. I'm confused about what oil to use in my differentials. The transfer case looks pretty straight forward...oil for a BW44-44 unit. Looks like Ravenol has this product. Dealer says it takes 3 pints. Ravenol says 1.4-1.8 liters (2.9-3.8 pints)...looks like I should buy 2 liters or 2 qts.

The Owners manual says to use Mopar Synthetic Gear Lubricant SAE 75W-140 (MS-8985) with 5 oz of Mopar Limited Slip Additive (MS-10111) for the rear differential. The local Ram Dealer's Parts Department tells me their computer says I should use SAE 75W-85. So wo do I trust? The Owner's Manual or the Dealer's computer? 75W-140 or 75W-85? I won't be buying the Mopar fluids since they are priced ridiculously. I live in Western Oregon so I don't deal with extreme ambient temperatures like in Arizona. I do tow a camp trailer fairly routinely in the summer. It appears most aftermarket lubricants already contain a LS additive. Do I need to worry about that? Dealer says it should take 4.22 pints. Ravenol says 2.2-2.9 liters (4.6-6.1 pints)....looks like the upper end is over 3 qts so sounds like 4 liters or 4 qts.

The Owner's Manual and the Dealer's computer are consistent for the front differential. Both say use GL-5 Synthetic Axle Lubricant SAE 75W-85. Any issues there? Dealer says it should take 2.3 pints. Ravenol says 1.1-1.4 liters (2.4-3.0 pints)...looks like the upper end is about 1.5 qts so sounds like 2 liters or 2 qts will work.

Any recommendations for lubricant brand. I found everything I need (I think) on the Ravenol site, but it appears to require placing an order. Is RedLine from O'Rielly's OK? What about Mobil products? Any others?

Appreciate any assistance you can offer.

Thanks
Vern

 

[DILLIGAF]

Amsoil website has all the right info on what you need for capacity and weights.

Just use a good synthetic gear oil its that simple. Amsoil ,RedLine Valvoline ect.

Id stick with 75W-140.

 

[Hemi395]

For the BW44-44 you can use the Amsoil MVATF (red label) in it. I've been running that in my 2013 44-44 for years with no issues and its way cheaper than the Mopar fluid. My tcase used to get hung up randomly going into 4Low or going back to 2wd from 4Low on the Mopar fluid. After changing to the Amsoil ATF I haven't had that problem.

The rear diff should have 75w140, not sure why the dealer is telling you 75w85. Every owner's manual for these trucks I've seen has shown 75w140 for the rear diff.

As mentioned, any good synthetic gear oil will be fine. With that said Redline/Amsoil are considered by many to be the best on the market for gear oil.

 

[Idahokid]

I just did my rear differential and I picked valoline 75w140 and it already has the fiction modifier in it so I didn’t have to buy it on the side.I will use valvoline 75w90 in the front. I will most likely use the mopar transfer case oil.Mines a 2016 so it’s the more expensive fluid.Amsoil would be my second pick on the transfer case fluid.Revanol also makes a transfer case fluid for the 2016 and newer BW44-44 .

 

[MRFREEZE57]

I used Redline 75-140 in the rear, it already has the LSD additive and it works fine, the TC I used Redline C+ also no issues and is half the price of the Mopar stuff.

 

[Nova John]

How often or how many miles do you go before rear fluid change?

 

[pacofortacos]

How often or how many miles do you go before rear fluid change?

Depends on how hard you use the truck.
I do mine every year or two since I tow at highway speeds for 1800 miles twice a year.

 

[Idahokid]

Manual says transfer case at 120,000 and check differentials every 30,000.I’m doing my transfer case this weekend at 111,000. I did my differentials with valvoline and month ago.It starting to get cold so I better do it now.I’ll be using the Amsoil Signature series transmission fluid that comes in the red bag.The mopar fluid is $60.

 

[ppine]

I would offer this. Modern quality lubricants are totally superior to what we used to use. Don't over think it. When in doubt go with the owner's manual. Pick one and look at the rest.

I have run into some dealer's with some odd ideas about maintenance. I was with my wife at the local Subaru dealer. They have a special on oil changes. Then they sat us down and gave us a recommended list of maintenance items that was about $400. My girl says "okay." I said "wait a minute, your intervals are half the time and mileage of the owner's manual." They gave me a rap about extreme conditions in Nevada. I called total ********.

If dealers conflict with the manual, go with the manual.

 

[ramffml]

So this is interesting and maybe where the confusion is. My owner's manual (2019 DT) recommends two different oils depending on gear ratio, and even for the 3.92 there are 2 different depending on "max tow" package or not.

First time I've seen this mentioned anywhere.

Which begs the question, is there any issue running the 75w-140 in a 3.21 like mine? I tow a lot and I'm hearing a groaning for a second when I turn sharp left/right from a dead stop (even unloaded). I have about 57,000 miles on the truck and a fair amount of towing was done with that, probably time for a fluid change.

 

[danielmid]

So this is interesting and maybe where the confusion is. My owner's manual (2019 DT) recommends two different oils depending on gear ratio, and even for the 3.92 there are 2 different depending on "max tow" package or not.

First time I've seen this mentioned anywhere.

Which begs the question, is there any issue running the 75w-140 in a 3.21 like mine? I tow a lot and I'm hearing a groaning for a second when I turn sharp left/right from a dead stop (even unloaded). I have about 57,000 miles on the truck and a fair amount of towing was done with that, probably time for a fluid change.

View attachment 530789

I've been running 75w-140 in my 3.21 for 3 years and roughly 50k miles (I'm at 110k ish miles now), and never had a problem. Red Line regular in my open diff up until the TruTrac install and now it runs Red Line NS. Lots of towing, hot and cold, cross country move pulling a camper and all.

 

[ramffml]

I've been running 75w-140 in my 3.21 for 3 years and roughly 50k miles (I'm at 110k ish miles now), and never had a problem. Red Line regular in my open diff up until the TruTrac install and now it runs Red Line NS. Lots of towing, hot and cold, cross country move pulling a camper and all.

Thanks, thought it might be better to open a new thread instead of hijack the OP:

diff fluid change on a 3.21

So I've been looking into changing the diff fluid on my truck, 5th gen with 3.21. Amsoil apparently does not make a product for it? On the webpage there is nothing listed for the 3.21. They do for the 3.92, but they apparently recommend using mopar/oem fluid for a 3.21. The manual calls for...

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