13 with Torsen diff, which gear oil?

[inyadreems]

Going to upgrade the gear fluid on my 13 with stock Torsen and 331's, considering RP/Amsoil/Mobil1 gear fluid for quieter and smoother operation. Curious what everyone is running and did anyone notice a difference in gear whine/noise with a fluid swap and if so, which brand? Also does the Torsen require friction modifier with these gear fluids?

Thanx

 

[Snoopy49]

From the 2013 GT500 Owners Manual Supplement.

Rear axle lubricant without cooler 4 pints (1.9L)
Rear axle lubricant with cooler 6 pints (2.8L)
Motorcraft® SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant
XY-75W85-QL / WSS-M2C942–A

Rear axle fluid friction modifier without cooler 4 oz. (118 ml)
Rear axle fluid friction modifier with cooler 6 oz. (177 ml)
Additive Friction Modifier XL-3 EST-M2C118-A

 

[inyadreems]

From the 2013 GT500 Owners Manual Supplement.

Rear axle lubricant without cooler 4 pints (1.9L)
Rear axle lubricant with cooler 6 pints (2.8L)
Motorcraft® SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant
XY-75W85-QL / WSS-M2C942–A

Rear axle fluid friction modifier without cooler 4 oz. (118 ml)
Rear axle fluid friction modifier with cooler 6 oz. (177 ml)
Additive Friction Modifier XL-3 EST-M2C118-A

Thanx for the info. Looking to upgrade from the MC fluid though.

 

[13 Cobra Toy]

Thanx for the info. Looking to upgrade from the MC fluid though.

This is what's going in my car. I used the 75W-140 in my 03 diff and never had a problem. Car was sold with 10K track miles. My car has the diff cooler.
https://www.motul.com/us/en-US/prod...gear-300-ls-75w90?f[range]=25&f[viscosity]=58

 

[Snoopy49]

Thanx for the info. Looking to upgrade from the MC fluid though.

You also asked about the friction modifier, so this was the easiest way to inform you and it also gives you the amount needed.
Good luck with your project.

 

[Gabe9195]

I know mine's not a Shelby, but I do have the Torsen and this is what I just put in it about a week ago:

 

[Norton]

I went with Amsoil Severe Gear 75W-90 and the requisite amount of their Slip Lock Gear Oil Additive.

 

[Tezz500]

I went with Amsoil Severe Gear 75W-90 and the requisite amount of their Slip Lock Gear Oil Additive.

this

 

[svtride]

Is friction modifier needed if there is a Torsen diff?

I thought the Torsen had no clutches thus no friction modifier required.

 

[Norton]

Is friction modifier needed if there is a Torsen diff?

I thought the Torsen had no clutches thus no friction modifier required.

The Owners Manual Supplement makes no distinction between Torsen and non-Torsen, only with/without cooler...

Rear axle lubricant without cooler 4 pints (1.9L)
Rear axle lubricant with cooler 6 pints (2.8L)
Motorcraft® SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant
XY-75W85-QL / WSS-M2C942–A

Rear axle fluid friction modifier without cooler 4 oz. (118 ml)
Rear axle fluid friction modifier with cooler 6 oz. (177 ml)
Additive Friction Modifier XL-3 EST-M2C118-A

 

[Snoopy49]

If it has a cooler, it has the Track Pack which requires the Performance Pack which includes the Torsen.

 

[Black Thunder 715]

I used Amsoil severe gear 75w90 too without issues.

 

[inyadreems]

Thanx for the responses. Notice some are going with the 75w140 instead of the 75w90, why? Anyone notice a reduction in gear whine with the Amsoil?

 

[cdh027]

Is friction modifier needed if there is a Torsen diff?

I thought the Torsen had no clutches thus no friction modifier required.

This is what I was told when I installed my 3.73's. I hope that's the case because I'm running straight amsoil without any friction modifier.

 

[SDBs13GT500]

This is what I was told when I installed my 3.73's. I hope that's the case because I'm running straight amsoil without any friction modifier.

Someone mentioned that if you have chatter then you would need friction modifier. I know Beast (AMSOIL Dealer) recommends the friction modifier He has a post in the Greasy spoon with what he recommends for 13/14 GT500s. The title of the discussion is First Oil Change GT 5w-50.

 

[Cman01]

I need to change my diff oil too along with the trans. I'm going to use Redline D4 ATF for the trans (bought it over 2 months ago just haven't had a chance to do it) but for the diff. at least for now I'm playing it safe and sticking with the Ford stuff until I do more research as to what to use there.

 

[carguy19]

I have the amsoil 75/140 oil in my car. No issues here.

The torsen doesnt take friction modifier. You dont need it.
The amsoil has a friction modifier in it anyway even though you dont need it.

 

[carguy19]

Guys in the owners manual, there is a little star in the specifications part of the manual where it lists the capacities that states that only the traction lock/non PP cars need friction modifier.

Whenever I get down to my garage in the next few days i can post a pic.

It definitely doesnt need friction modifier if you have torsen.

This can also be verified by going to the website that makes the differential.

 

[Snoopy49]

Since only the PP cars have Torsens and only Track Pack cars have a differential cooler and you can't get the Track Pack without the PP, how do explain the quote below?
What page number was the little star found on and which version of the manual?

From the 2014 Mustang Service Manual.

NOTE: Service refill capacities are determined by filling the axle to a level of 5mm below the bottom of the fill hole with the axle at ride height.

If equipped with a differential oil cooler, Remove the axle plug and fill the axle with 1.89-2.01L (4-4.25 pt) of axle lubricant and a additional 4.0 oz of friction modifier additive, then use a scan tool to operate the oil cooler pump and add a additional 1.10L (2 pt) of axle lubricant and a additional 2 oz of friction modifier and install the filler plug.
Tighten to 30 Nm (22 lb-ft).

This is from the 2013 Mustang Owners Manual - 3rd Printing - Page 298

Add 4 oz. (118 ml) of Additive Friction Modifier XL-3 or equivalent meeting Ford specification EST-M2C118-A for complete refill of Traction-Lok or TORSEN® axles.

 

[carguy19]

Since only the PP cars have Torsens and only Track Pack cars have a differential cooler and you can't get the Track Pack without the PP, how do explain the quote below?
What page number was the little star found on and which version of the manual?

From the 2014 Mustang Service Manual.



This is from the 2013 Mustang Owners Manual - 3rd Printing - Page 298

I cannot get the manual until the weekend, its in my garage, but I will get a photo/page #.

I also confirmed this with Torsen (the company that makes the differential) and with my tuner/mechanic who is very knowledgeable