Diff gear oil change--anti slip additive?

[JJWW]

Hey all,

2019 1500 classic with 5.7L. I want to change my gear lube in the rear diff but I'm not sure if I need the anti slip additive. It has the 3.21 gear ratio and from what I've read 75W90 gear is what I need. I didn't get the max tow package but I can't figure out if i need the anti slip additive for the limited slip diff.

Can someone advise? Thank you!

 

[Badger 13]

If you buy quality gear lube like Amsoil, Redline, or a few others, the additive is already in it.

 

[18CrewDually]

And even if you don't have LS, the additive won't hurt anything.

 

[dsherman26]

I had to use the VIN lookup tool on the Ram site to find out whether I had the limited slip differential option. Don't know if the 3.21 has a limited-slip version of it, but I didn't have it. Kind of a non-issue anyway, the Mobil1 gear oil I used had the additives in it.

 

[Curmudgeon]

Hey all,

2019 1500 classic with 5.7L. I want to change my gear lube in the rear diff but I'm not sure if I need the anti slip additive. It has the 3.21 gear ratio and from what I've read 75W90 gear is what I need. I didn't get the max tow package but I can't figure out if i need the anti slip additive for the limited slip diff.

Can someone advise? Thank you!

If you need it, and you may want to bookmark it in case you need it again, here is the site that @dsherman26 is referring to. Make sure all letters are in CAPS...

https://fcagroup.my.site.com/RAM/s/equipment-listing

 

[04fxdwgi]

I had to use the VIN lookup tool on the Ram site to find out whether I had the limited slip differential option. Don't know if the 3.21 has a limited-slip version of it, but I didn't have it. Kind of a non-issue anyway, the Mobil1 gear oil I used had the additives in it.

My 3.21 is a Limited Slip, so yes, it is available.

 

[Wild one]

Hey all,

2019 1500 classic with 5.7L. I want to change my gear lube in the rear diff but I'm not sure if I need the anti slip additive. It has the 3.21 gear ratio and from what I've read 75W90 gear is what I need. I didn't get the max tow package but I can't figure out if i need the anti slip additive for the limited slip diff.

Can someone advise? Thank you!

Just for the record the earlier trucks called for 75W-140,the rear end didn't change,but the claimed milege numbers did.
Everytime they go after better fuel milege numbers,the fluids all get lighter,which usually isn't conducive to better longevity from the driveline.
As 04 stated above the 3.21's are available with limited slip,my truck came with 3.21's and limited slip,and calls for 75W-140

 

[JJWW]

If you need it, and you may want to bookmark it in case you need it again, here is the site that @dsherman26 is referring to. Make sure all letters are in CAPS...

https://fcagroup.my.site.com/RAM/s/equipment-listing

Thanks curmudgeon. I looked up my vin but it didn't say limited slip anywhere in the tech specs. I'm not even sure where that might be listed. All the gear ratios are there though.

 

[Wild one]

Thanks curmudgeon. I looked up my vin but it didn't say limited slip anywhere in the tech specs. I'm not even sure where that might be listed. All the gear ratios are there though.

Little tidbit for you 75W-140 acts the same as 75W-90 until the diff gets hot,then it starts to become a better diff fluid for absorbing the loads placed on the diff.They switched to a lighter diff fluid to gain that 0.001 mpg gain,not to prolong the life of your rear diff

 

[Curmudgeon]

Thanks curmudgeon. I looked up my vin but it didn't say limited slip anywhere in the tech specs. I'm not even sure where that might be listed. All the gear ratios are there though.

It might take some careful looking, mine is 8 pages. It starts with "Standard Equipment" then several pages later it shows "Optional Equipment" and that is
where it is hidden. As you can see below it is surrounded by an odd mix, and the copy/paste below is just a small sample.

FULL LENGTH FLOOR CONSOLE
FOLDING FLAT LOAD FLOOR STORAGE
ROTARY SHIFTER-BRIGHT
ALL AUTOMATIC TRANSMISSIONS
8-SPD AUTO 8HP70 TRANS (BUY)

ANTI-SPIN DIFFERENTIAL REAR AXLE

5.7L V8 HEMI MDS VVT ENGINE
REAR WINDOW DEFROSTER

Here is another site you might find interesting, though it might not be any easier to find. Using your VIN you can lookup an exact, full-color image of your window sticker, including all the various factory prices. Of course anything altered by individual dealers will not be shown...

https://windowstickerlookup.com/
.

 

[Curmudgeon]

@JJWW - Hmmm, both sites are coming up blank for my VIN, I wonder if they have a 10-year cutoff. My 2014 became a 10-year old as of midnight last night.

Fortunately I saved hard copies of both. Here is a photo of the area on the window sticker where the rear diff is mentioned...

 

[Jas34]

I used Valvoline in mine because I like the squeeze bottles. It comes with the additive and worked fine in my 3.21 antispin. Rear on my 2017 takes the heavier oil, front takes the lighter oil.