2016 Mustang Differential Oil Change

[Ike]

I've drained and replaced the oil with 1.6 quarts of 75w85 and 4 oz of XL3 friction modifier, but the oil level is about 15 mm below the oil fill plug. I've read that it should be 9 mm. Should I add additional oil to get to 9 mm, or leave with the quantity specified in the owners manual as I've done?

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[EFI]

I've never heard of the mm rule, just a volume as mentioned.

I always put in enough to just barely leak out of the fill plug which was about 1.7 quarts. You're splitting hairs at this point, if you put in 1.6 quarts then you're fine.

 

[Elp_jc]

I'd always go by the 'dipstick', which in this case is the 9mm... just make sure that's what the service manual says. You probably drained your diff longer than other folks, hence the slightly lower level. I've heard people filling it until fluid drains out, which is typically the way to do it. It's better to have it right on the money, but between 15mm (underfilled) and to the fill plug (overfilled), I'd go with the latter .

 

[db252]

Make sure the car is level checking the fluid. Some jack up the rear to do this since they don’t have a lift. If the rear is lifted only, the fluid level will read wrong.

 

[blakedanatural]

I plan on doing mine this weekend . I have a 2015 Mustang Gt Premium and my question is are you using Motorcraft,Amsoil,Purple or Mobil One? Also the manual says use 75w85 but the Mobil is 75W90 will this harm anything? My Mustang has 85000 miles.

 

[db252]

You can use BG fluid from opmustang.com and get the kit that gives enough fluid, a pump and the modifier already mixed in.

 

[Elp_jc]

Also the manual says use 75w85 but the Mobil is 75W90 will this harm anything?

Not at all. Many owners use 75w110, and even 75w140. I'd say 75w90 is pretty much the equivalent of stock.

 

[blakedanatural]

Not at all. Many owners use 75w110, and even 75w140. I'd say 75w90 is pretty much the equivalent of stock.

Thank you and you dont have to use motorcraft right?

 

[Elp_jc]

Of course not, but make sure whatever you use, complies with Ford's spec, especially if still under warranty. And also don't forget about the FM additive needed (if not already mixed in). If you want to use Motorcraft, I'd use the OEM one, plus the little bottle of FM required. Good luck.

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