Let's Talk Differentials

[MTF]

Here's the Office Ford updated link to gear oil chart.

https://www.fcsdchemicalsandlubricants.com/Main/quickref/axlelubeUS.pdf

 

[zemuron99]

Ordered thru the LL website:

https://www.lubelocker.com/product/llr-f975

I agree, no one will likely ever complain about Amsoil products. I'm going w/M-1 long-term as I've had excellent results with their motor oils, and my last two changes in the Raptor both had great reports from Blackstone labs.

I'd change my fluid rightnow if I were you, knowing how mine looked at about the same mileage. In my other thread someone commented 'it looks like used gear oil'. True, but I'd add 'with 100k miles of hard (ab)use, towing, sustained high-speeds, etc.'. I never drained anything out of my Tacoma that looked like that. The sooner all those wear-in particles get out of the diff the less wear they'll cause. Have fresh clean oil in it now, and in another 1k miles or so will change that out again, and can keep the M-1 in there for >100k I'll bet. Not going to do the front just yet, haven't used 4wd enough to make it, or the t-case, worthwhile just yet.

FWIW, if you do go w/the Ford performance cover, it seems to hold more than with the regular diff cover. I put in 3 bottles (quarts) of the Lucas and it's about 1 pinky-joint below the lower fill hole. When I change it to the M-1 I'll have 4 quarts on hand just to be sure I get it up to the bottom of the first fill hole (there's two in the Ford performance cover).

 

[Loufish]

Don't worry about getting the oil level RIGHT to the fill hole...I run my oil levels a little below to reduce pressure on the wheel bearing seals...did this on over 100 rear ends without a single issue...

 

[Flash1034]

So on the Ford Performance Cover, the correct fill is to the bottom of the lower hole...correct?

 

[Badgertits]

Here's the Office Ford updated link to gear oil chart.

https://www.fcsdchemicalsandlubricants.com/Main/quickref/axlelubeUS.pdf



View attachment 129473 View attachment 129474

Only one option listed for the f150 raptor front diff showing it DOES need friction modifier XL3, says rear N/A

But Raptors can be had w/ standard or Torsen front diffs- does this mean they both need friction modifier or only one of the other??

 

[NASSTY]

Only one option listed for the f150 raptor front diff showing it DOES need friction modifier XL3, says rear N/A

But Raptors can be had w/ standard or Torsen front diffs- does this mean they both need friction modifier or only one of the other??

Neither Raptor diff should need friction modifier. None of them have clutches, not even the Torsen diff.
I don't know why it needs it? TrueTracs are similar and don't need friction modifier.

 

[MTF]

Neither Raptor diff should need friction modifier. None of them have clutches, not even the Torsen diff.
I don't know why it needs it? TrueTracs are similar and don't need friction modifier.

That's what Ford wants

Torsen's Website:
https://torsen.com/tbr-lube-friction-modifier/

Basically they say it's beneficial to use.

 

[zemuron99]

That's what Ford wants

Torsen's Website:
https://torsen.com/tbr-lube-friction-modifier/

Basically they say it's beneficial to use.

Not really...they say: "our (Torsen) friction properties are different than that of a clutch plate differential," "In a helical gear diff (Torsen), however, the stick-slip tends to show up as an audible noise, described by some as a “rusty screw” noise, or as a squeak or moan. You tend to hear it in very low-speed turns, when the steering is at or near full-lock." "So, the bottom line is it’s up to you.". If you operate in a lot of circumstances where you're hearing noise from the Torsen action, add a few ounces. If you're not hearing noise from the activation of the Torsen system in your front, it won't add any benefit.

Ford probably advocates adding it to prevent customer complaints i.e "noisy front diff". It probably comes from the factory that way (with friction modifier added). If you change the front diff oil, it's up to you to add the modifier or not. Beware though, not adding it may give Ford cause to deny warranty claims related to front diff failures...i.e. you didn't maintain according to manufacturer recommendations.

 

[MTF]

Well, "Beneficial", who is going to try it without the modifier?
Only to find out what Ford found out, there is some noise.
So now you have to drop the cover again and do it right.