Front/Rear Diff Oil Type and Fill Level

[mpeychev]

Hello all!

I've tried to look all over Google and Forums for this answer - however, I am having zero luck with a definitive.

I have a 2018 Raptor and I am wanting to change the fluids on the both the front and rear diff, plus the transfer case. Between certain YouTube comments, Amsoil's website, and the Raptor's owner's manual and supplement book I am getting all types of different answers?

How much fluid should be used, and what type of fluid exactly? I'm keeping the stock diff covers. Thanks in advance!

 

[JohnyPython]

I plan on doing mine in the next couple months. I like FTML on YT.

I don’t have the owner’s manual here but that’s what I would use as gospel. Use the correct spec oil and volume and you should be good. Always good to get a extra quart.

I have had excellent success with Amsoil’s site in terms of specs so I would cross reference that.

 

[StraightSixM2C]

Check your raptor supplement manual to make sure it’s the same. This is for a 2020 with the Torsen front diff.
Front : 2qt of 75w85
Rear: 3qt of 75w85
T-case: 2 qt Mercon LV
I have the ford performance diff cover so I add 1 qt. Don’t get anything with a friction modifier in it.

 

[Nex]

I am running this is my diffs. 2 bags per diff.

 

[ALRaptor]

My 2019 Raptor supplement shows a transfercase fluid level of 1.5QTS. @FordTechOne can you confirm this?

 

[FordTechOne]

My 2019 Raptor supplement shows a transfercase fluid level of 1.5QTS. @FordTechOne can you confirm this?

View attachment 397504

I’m showing 1.9 quarts. That supplement may be an earlier print that is incorrect.

 

[Badgertits]

I am running this is my diffs. 2 bags per diff.

View attachment 397503

Should be 3-ish for the rear

I’m using same fluid, Amsoil gear oil is great stuff, their ATF makes a noticeable improvement in shift feel every time I swap it out on my manual trans C5Z (yeah sounds odd but Amsoil recommends their synthetic ATF for the Tremec T56) - which made me a real believer in their stuff (on top of engine oil analysis always coming back clean)

 

[Space Ghost]

I am running this is my diffs. 2 bags per diff.

View attachment 397503

It says it has friction modifier in it, is that problem in our trucks or do we not need it and its otherwise fine to use?

View attachment 397493
Check your raptor supplement manual to make sure it’s the same. This is for a 2020 with the Torsen front diff.
Front : 2qt of 75w85
Rear: 3qt of 75w85
T-case: 2 qt Mercon LV
I have the ford performance diff cover so I add 1 qt. Don’t get anything with a friction modifier in it.

Are you filling from top fill port or the next one down? Supposedly the top one is only for lifted applications due to the pinion gear angle, couldnt get a good answer on fill levels for our trucks.

 

[Nex]

I’m showing 1.9 quarts. That supplement may be an earlier print that is incorrect.

Should be 3-ish for the rear

I gave Ford 4 qt bags when they replaced my rear diff cover. They gave 2 bags back. Need to have the front swapped out still.

It says it has friction modifier in it, is that problem in our trucks or do we not need it and its otherwise fine to use?

I have not noticed any issues.

 

[ALRaptor]

I’m showing 1.9 quarts. That supplement may be an earlier print that is incorrect.

Would filling until it runs out of fill port suffice you think?

@FordTechOne