2016 Mustang Differential OIl Change

[ant]

Originally Posted By: 2015_PSD
Originally Posted By: ant
Originally Posted By: 2015_PSD
Originally Posted By: ant
You're right probably don't need the most expensive oil, just need one fit for purpose. Do you see any issue with the 75w90 given that it's 50% higher viscosity?
50% higher viscosity than what?
Higher than the factory 75w85
I am not following you. How can 75W-90 be 50% higher viscosity over 75W-85?


Motorcraft @ 100°C is 11.5cSt while the 75w90s are 15.5-16.5cSt at 100°C,

66cSt vs 100-120cSt @40°C

 

[CarbonSteel]

Originally Posted By: ant
Motorcraft @ 100°C is 11.5cSt while the 75w90s are 15.5-16.5cSt at 100°C, 66cSt vs 100-120cSt @40°C
OK; I am with you. I am not sure what it would mean, but from what I see most non-OEM oil manufacturers recommend 75W-90 for your application. I have not looked at Mustangs in a while, but the 2014 model specified 75W-140 (I think that was a different axle).

 

[MolaKule]

75W110 is a good all weather, all around grade and you can't go wrong with Amsoil Severe Gear.

 

[CarbonSteel]

Originally Posted By: MolaKule
75W110 is a good all weather, all around grade and you can't go wrong with Amsoil Severe Gear.

 

[Y_K]

Thank you. I believe it was manufactured in Sweden, but it's been a while..

 

[wtd]

I changed the rear diff fluid in my 2014 Mustang GT at around 3,600 miles when I installed an aluminum finned Ford cover on it. Mine specs 75W-140 and I used the Motorcraft stuff with the Motorcraft friction modifier. The factory fluid looked nasty. It was gray with a lot of sparkle to it.

 

[CarbonSteel]

Originally Posted By: wtd
I changed the rear diff fluid in my 2014 Mustang GT at around 3,600 miles when I installed an aluminum finned Ford cover on it. Mine specs 75W-140 and I used the Motorcraft stuff with the Motorcraft friction modifier. The factory fluid looked nasty. It was gray with a lot of sparkle to it.
The gray is a normal color for the factory rear axle on a Ford. Did it look like this?

 

[RF Overlord]

When I changed the fluid in my 2000 Grand Marquis right after purchase in 2012, it looked more like silver paint. Replaced it with M1 75W-90. No issues since.

 

[MaximaGuy]

Anything that doesn't look engine oil scares me - wouldn't know if it is dirty or otherwise.

 

[bdcardinal]

Originally Posted By: 2015_PSD
Originally Posted By: wtd
I changed the rear diff fluid in my 2014 Mustang GT at around 3,600 miles when I installed an aluminum finned Ford cover on it. Mine specs 75W-140 and I used the Motorcraft stuff with the Motorcraft friction modifier. The factory fluid looked nasty. It was gray with a lot of sparkle to it.
The gray is a normal color for the factory rear axle on a Ford. Did it look like this?

I vaguely remember the factory fluid looked similar to that in mine when I drained it at 5K. My Mustang has drain and fill plugs on the cover so I didn't have to pull the cover.

 

[wtd]

Originally Posted By: bdcardinal
Originally Posted By: 2015_PSD
Originally Posted By: wtd
I changed the rear diff fluid in my 2014 Mustang GT at around 3,600 miles when I installed an aluminum finned Ford cover on it. Mine specs 75W-140 and I used the Motorcraft stuff with the Motorcraft friction modifier. The factory fluid looked nasty. It was gray with a lot of sparkle to it.
The gray is a normal color for the factory rear axle on a Ford. Did it look like this?

I vaguely remember the factory fluid looked similar to that in mine when I drained it at 5K. My Mustang has drain and fill plugs on the cover so I didn't have to pull the cover.


Yes it looked like that. The cover I installed is the one that bdcardinal has on his car. It also has the fill and drain plugs on the cover.

 

[ant]

Originally Posted By: Anthony
I changed the Diff Lube in my 17 Mustang GT about 300 miles ago. I went with Amsoil Severe Gear 75w110. I’m happy so far mainly because I did not add any Friction Modifers and so far the diff has not acted weird in tight turns etc. I don’t track the car but I am hard on it at times so I liked the idea of upping the viscosity slightly.



How much oil did you use? I went with the 75w90 and filled until the level reached the fill plug hole, but this may now be overfilled as I put about 6oz more than the owners manual indicates for the capacity.

 

[Whimsey]

Originally Posted By: ant
Originally Posted By: Anthony
I changed the Diff Lube in my 17 Mustang GT about 300 miles ago. I went with Amsoil Severe Gear 75w110. I’m happy so far mainly because I did not add any Friction Modifers and so far the diff has not acted weird in tight turns etc. I don’t track the car but I am hard on it at times so I liked the idea of upping the viscosity slightly.



How much oil did you use? I went with the 75w90 and filled until the level reached the fill plug hole, but this may now be overfilled as I put about 6oz more than the owners manual indicates for the capacity.


I believe it's usually common, not always, to fill up the diff a bit below the fill plug to allow for expansion. If you filled it till it spills out there is a possibility of some being vented out if it gets hot, not a big deal though.

Whimsey

 

[Anthony]

Originally Posted By: ant
Originally Posted By: Anthony
I changed the Diff Lube in my 17 Mustang GT about 300 miles ago. I went with Amsoil Severe Gear 75w110. I’m happy so far mainly because I did not add any Friction Modifers and so far the diff has not acted weird in tight turns etc. I don’t track the car but I am hard on it at times so I liked the idea of upping the viscosity slightly.



How much oil did you use? I went with the 75w90 and filled until the level reached the fill plug hole, but this may now be overfilled as I put about 6oz more than the owners manual indicates for the capacity.


Every source I could find online said 1.6 quarts.
I drained it an measured exactly 1.6 quarts that came out so I refilled with 1.6

 

[rsalan]

Just did my rear diff and MT yesterday. The old rear diff fluid looked like that too. Filled up with Motul GEAR 300 LS 75w90.