Differential and MT-86 fluid change procedure

[Walt]

I'm about to change the rear differential and the MT-86 fluid for the first time. Is there any special procedure I should follow or do you just fill both on level ground until the fluid starts dripping back out of the filler hole? I have a performance pack equiped 2017 Mustang Ecoboost. It's an European spec so I don't know if it's any different but I don't think it has the Torsen differential.

Since BG fluid isn't available anywhere locally, I was thinking to use Motul Gear 300 LS 75W-90 for the differential and Ravenol mtf-2 75w-80 for the transmission. What are your thoughts on those fluids for track driving (road course) and cruising in all conditions (even snow)?

The reason I want to go with aftermarket fluids is because I can't get the OEM Motorcraft fluid at the dealer or any other place locally.

Not sure if I should get the 75W-140 version or stick with 75W-90.

I just got back from a track day at Spa Francorchamps and it's been the 5th track day in total so I think a change is due. From now on I think I'll just change it annually.

Fluids:
https://www.motul.com/us/en-US/products/gear-300-ls-75w90
https://www.ravenol.de/en/product-r...ual-transmissions-1/ravenol-mtf-2-sae-75w-80/

Sponsored

 

[Elp_jc]

I want to change those fluids early too, but rather than now at 1K miles, will wait until next oil change at 6K. But had the same dilemma as you're having. Was told by Redline that 75W140 was too much; that it was going to cause a lot of unnecessary friction when not at the track. Since I won't track my car, I'll probably pass on that. He said to stick to the stock 75W85, but I'll go with 75W90. If you could find 75W110, it could be a good compromise, but if you're going to use the car in winter, I'd also skip the 140.

As far as the tranny, it needs a DCT fluid, but the BG is not, and many pre-2018 owners use it, so you should be fine there. I'll probably stick to the OEM fluid. Wanted to get something better, but Redline tech guy said he didn't recommend their DCT-F for my 2019 (MT-82 D4), hence sticking with OEM, which is also fully synthetic, reportedly. Hope this helps.

 

[Walt]

I want to change those fluids early too, but rather than now at 1K miles, will wait until next oil change at 6K. But had the same dilemma as you're having. Was told by Redline that 75W140 was too much; that it was going to cause a lot of unnecessary friction when not at the track. Since I won't track my car, I'll probably pass on that. He said to stick to the stock 75W85, but I'll go with 75W90. If you could find 75W110, it could be a good compromise, but if you're going to use the car in winter, I'd also skip the 140.

As far as the tranny, it needs a DCT fluid, but the BG is not, and many pre-2018 owners use it, so you should be fine there. I'll probably stick to the OEM fluid. Wanted to get something better, but Redline tech guy said he didn't recommend their DCT-F for my 2019 (MT-82 D4), hence sticking with OEM, which is also fully synthetic, reportedly. Hope this helps.

Do you know if there's any specific fill procedure or do you just fill both fluids until it starts dripping out of the fill hole? I read somewhere that the GT requires a few mm under the filler hole for the MT82 and the ecoboost doesn't, but I can't seem to find the thread again. I want to be sure I do it correctly.

As long as the fluid meets the required spec (WSS-M2C200-D2) it should be fine to use in the MT82. The main reason they recommend a DCT fluid is probably just to have one less fluid to stock on the shelf.

 

[Elp_jc]

The notes and research I did showed the Torsen fill level to be 1/3" (9mm) below the fill line, but some folks filled it to the fill hole, and reported to have poured about the correct amount (1.8 qts, I think), so who knows. And the tranny supposedly at the fill plug level. Some filled the exact amount (I think 2.7 qts), and it was right at the fill hole, so not worth doing it the hard way. But what I'll do is check the level on both before draining anything, and decide what to do. If both are at or very close to the fill plug, I'd just fill them up until fluid pukes out.

Finally, keep in mind if your diff is not a Torsen, it might be different than mine. Ask somebody with a service manual of your year to give you that info. Tranny should be the same, even if not a D4 (2018+). Good luck.

 

[Walt]

The notes and research I did showed the Torsen fill level to be 1/3" (9mm) below the fill line, but some folks filled it to the fill hole, and reported to have poured about the correct amount (1.8 qts, I think), so who knows. And the tranny supposedly at the fill plug level. Some filled the exact amount (I think 2.7 qts), and it was right at the fill hole, so not worth doing it the hard way. But what I'll do is check the level on both before draining anything, and decide what to do. If both are at or very close to the fill plug, I'd just fill them up until fluid pukes out.

Finally, keep in mind if your diff is not a Torsen, it might be different than mine. Ask somebody with a service manual of your year to give you that info. Tranny should be the same, even if not a D4 (2018+). Good luck.

Thanks, I think that I'm also going to measure the old fluid so I can try and match that amount just to be sure. I've bought a syringe pump with measurements on the side so it shouldn't be too hard to match the exact amount. Good luck with your fluid change!

 

[ice445]

The diff requires a friction modifier/additive I'm fairly sure so keep that in mind

 

[Walt]

The diff requires a friction modifier/additive I'm fairly sure so keep that in mind

Do you need the friction modifier from Motorcraft with aftermarket fluids? I would assume that they already have their own additives included in the bottle. The Motul Gear 300 LS 75W-90 says for Limited Slip differentials so I thought it had some sort of additive.

Could anyone confirm this? Do you need the friction modifier with aftermarket fluids?

 

[Elp_jc]

With most you don't, but make sure it says that on the bottles. I wouldn't add any more if they already have it. Please post your experience with whatever you use .

 

[Walt]

With most you don't, but make sure it says that on the bottles. I wouldn't add any more if they already have it. Please post your experience with whatever you use .

Will do, I've just received the fluids so now it's waiting for the transfer pump I've ordered to arrive. I have chosen the fluids I mentioned in my first post. The one for the differential (Motul) says Limited Slip on the bottle so I guess I don't need an additive. The transmission fluid (Ravenol) doesn't mention it but as far as I'm aware the transmission doesn't need the additive since the OEM fluid comes without one too. The Ford WSS-M2C200-D2 label is on the bottle so I'm probably fine there.

When I receive the pump and have some more free time I will do the change and follow up this thread.

 

[Elp_jc]

Yeah, tranny doesn't need FM. Let us know how you like that Ravenol fluid; haven't heard of it before. And may I ask where you bought the transfer pump? I need to buy 2 before doing it myself (don't want to mix fluids, so one for each). Thanks man.

 

[Walt]

Yeah, tranny doesn't need FM. Let us know how you like that Ravenol fluid; haven't heard of it before. And may I ask where you bought the transfer pump? I need to buy 2 before doing it myself (don't want to mix fluids, so one for each). Thanks man.

I bought 2 500cc syringe style pumps (or like some say penis pump lol) for 5 bucks each. I bought them locally in a harbor freight kind of place. I live in Europe though so giving you a link won't be helpful.

It looks like this: https://www.amazon.com/ABN-Automotive-Transfer-Syringe-Bottle/dp/B075NKV4CR

But I recommend getting it somewhere else than Amazon for much cheaper. Your local Autozone or harbor freight should have those.

 

[Elp_jc]

Thanks brother. But it'd be a PITA with those. I'm going to get an actual pump, which you thread on the bottle, and just pump until empty, and the fluid exits thru a hose, so it's quicker, and less messy IMO. But with the 1.x qts for the diff and 2.x for the tranny, it shouldn't be too bad. Let us know when you're done how much of a hassle it was .

 

[Rapid Red]

Will do, I've just received the fluids so now it's waiting for the transfer pump I've ordered to arrive. I have chosen the fluids I mentioned in my first post. The one for the differential (Motul) says Limited Slip on the bottle so I guess I don't need an additive. The transmission fluid (Ravenol) doesn't mention it but as far as I'm aware the transmission doesn't need the additive since the OEM fluid comes without one too. The Ford WSS-M2C200-D2 label is on the bottle so I'm probably fine there.

When I receive the pump and have some more free time I will do the change and follow up this thread.

This is from the user manual 2020 GT, get online. Down load the PDF user manual for your car & verify .

Rear Axle Capacities ** 1.6 qt (1.5 L)

1 For complete refill of our limited slip axles, add 3.28 fl oz (97 ml) of Additive Friction
Modifier XL-3
or equivalent meeting specification EST-M2C118-A.
Include this friction modifier in the total fluid capacity.
>>>>>>Our rear axles contain a synthetic lubricant that does not require changing unless you submerge the axle in water.<<<<<<<


* * Manual tran 2.7qt

Cheers

 

[Walt]

Thanks brother. But it'd be a PITA with those. I'm going to get an actual pump, which you thread on the bottle, and just pump until empty, and the fluid exits thru a hose, so it's quicker, and less messy IMO. But with the 1.x qts for the diff and 2.x for the tranny, it shouldn't be too bad. Let us know when you're done how much of a hassle it was .

I wanted a screw on pump too but couldn't find one for my bottle cap size. I used the syringe pump before when I was flushing the brakes and it wasn't too bad. I guess we'll see

Sponsored