Rear Diff Fluid?

[bruker]

What's the correct rear diff fluid for a 2020 Edge and where did you get it from? Thanks

[1004ron]

Looks like the owner's manual calls for:

 

Rear Axle

Variant	Quantity
All.	28.1 ± 1.0 fl oz (830 ± 30 ml)

 

Materials

Name	Specification
Motorcraft® Disconnect Rear Drive Unit Fluid XY-75W-QL	-

 

MOTORCRAFT XY75WQL Gear Oil | Shop Now at RockAuto

[Samurai Edge]

The Owner's Manual?  That's a funny place to look.   😉

 

That particular option is ridiculously / outrageously expensive.  This is what I use :  Redline MT-LV 70W/75W  ( Full Synthetic )

 

[omar302]

2 hours ago, Samurai Edge said:

The Owner's Manual?  That's a funny place to look.   😉

 

That particular option is ridiculously / outrageously expensive.  This is what I use :  Redline MT-LV 70W/75W  ( Full Synthetic )

 

 

The Motorcraft oil is specifically made(formulated) for the Ford "Disconnect Rear Drive Unit". Hence assume it is not a general gear oil like other makes. The Motorcraft specs (link) states:

 

• Motorcraft® SAE 75W Disconnect Rear Drive Unit Fluid is specifically formulated for Ford disconnect rear drive units with a low offset hypoid gear
• Developed with a lower viscosity to improve axle efficiency and fuel economy
• Motorcraft® SAE 75W Disconnect Rear Drive Unit Fluid is formulated with synthetic base stocks, friction modifiers, antiwear and extreme pressure additives to provide gear protection and smooth clutch operation
• Use only in Ford Disconnect Rear Drive Units
• DO NOT use in conventional high-offset hypoid gear axles where SAE 75W-85, 75W-90, 80W-90 or 75W-140 is recommended

[Samurai Edge]

59 minutes ago, omar302 said:

 

The Motorcraft oil is specifically made(formulated) for the Ford "Disconnect Rear Drive Unit". Hence assume it is not a general gear oil like other makes. The Motorcraft specs (link) states:

 

• Motorcraft® SAE 75W Disconnect Rear Drive Unit Fluid is specifically formulated for Ford disconnect rear drive units with a low offset hypoid gear
• Developed with a lower viscosity to improve axle efficiency and fuel economy
• Motorcraft® SAE 75W Disconnect Rear Drive Unit Fluid is formulated with synthetic base stocks, friction modifiers, antiwear and extreme pressure additives to provide gear protection and smooth clutch operation
• Use only in Ford Disconnect Rear Drive Units
• DO NOT use in conventional high-offset hypoid gear axles where SAE 75W-85, 75W-90, 80W-90 or 75W-140 is recommended

 

Good repeat of the manufacturer's position.  It really means nothing.

As long as someone uses an oil, gear oil, etc., that, at a minimum, meets the standards of the specified oil, gear oil, etc., then said oil performs the same, at a minimum, of the specified oil.

 

Redline MT-LV 70W/75W  ( Full Synthetic ) meets that specification.

https://www.redlineoil.com/mt-lv-70w75w

 

[omar302]

22 minutes ago, Samurai Edge said:

 

Good repeat of the manufacturer's position.  It really means nothing.

As long as someone uses an oil, gear oil, etc., that, at a minimum, meets the standards of the specified oil, gear oil, etc., then said oil performs the same, at a minimum, of the specified oil.

 

Redline MT-LV 70W/75W  ( Full Synthetic ) meets that specification.

https://www.redlineoil.com/mt-lv-70w75w

 

 

Generally I would agree with you, but I have not seen Ford develope a "specific" oil for no reason. Usually their oils have some spec and the manual would state you should use an oil that meets their minimum spec, for the "disconnect" PTU and RDU used on 2019+ Edges, I don't recall reading the same. 

 

In the link for for redline MT-LV specs you posted, it is clearly stated:

• MT-LV, MTL, MT-85 & MT-90 are not for use in differentials with hypoid gears

Additionally, the OEM compatibility does not include Ford's disconnect oil. 

[Samurai Edge]

 

 

9 minutes ago, omar302 said:

 

Generally I would agree with you, but I have not seen Ford develope a "specific" oil for no reason. 

 

I don't disagree with you but that doesn't mean they are the only game in town.  I do use Motorcraft oils because  1.)  As you said above   and   2.) Many times they are equal or lower in price than a competitor, ie; Redline or Motul.  However, the RDU Disconnect fluid is stupidly overpriced so I went looking for an alternative.

 

When I called Redline's Tech Service line, they stated that their MT-LV 70W/75W  ( Full Synthetic ) meets that specification of the Motorcraft Disconnect Rear Drive Unit Fluid XY-75W-QL.

 

I don't just swap out one for another without researching alternatives.  As far as I could find, only Redline clearly stated that their MT-LV 70W/75W  ( Full Synthetic ) meets that specification of the Motorcraft Disconnect Rear Drive Unit Fluid XY-75W-QL.  No one else did.

 

I'll spend 1/2 the price on a known product line that I have been using for years.

[1004ron]

Generally the differential oils contain friction modifiers which cause issues with wet clutches. 

 

Similar reason why its not good to use car engine oil in a motorcycle due to the wet clutch - motorcycle engine oil does not contain friction modifiers.

 

Redline and Amsoil are top rated, so if they put it in writing that their oil is compatible I'd trust that.

The Redline website kind-of indicates that its compatible.

 

Interesting discussion here:

https://bobistheoilguy.com/forums/threads/rear-differential-rdu-fluid-amsoil-alternative.401168/

 

And here:

https://www.mavericktruckclub.com/forum/threads/rdu-rear-diff-non-oem-fluid-change-motocraft-xy-75w-qd-is-roughly-equivalent-to-a-synchromesh-gl-4-manual-transmission-fluid-not-a-gear-oil.75331/