Another trans/diff oil post - 75w90 or 75w140 help?

[Nickel]

Hello all. My 2016 GTPP has some pretty stubborn shifting problems which my 2017 didn't have. It's just not very smooth in all gears. I bought this car with 16,700 miles and now it has over 17K. I've owned dozens of rear wheel drive cars and always do my own work. I plan to upgrade to the Steeda clutch spring and want to change out the fluids.

Going to do the BG Synchro Shift 2 kit with everything I need. I don't necessarily track my car, but I accelerate hard all of the time, and slide the car sometimes, and I also spend a lot of time on windy roads like Deal's Gap and 181 here in NC. With that being said, would it be smarter for me to go with the 75w140? I'm unsure whether or not I have the differential cooler.

Thanks!

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[BmacIL]

75W90 since you're not doing extended track sessions.

 

[Nickel]

75W90 since you're not doing extended track sessions.

I just ordered the Steeda clutch spring and the full kit for the trans and diff. Hopefully this pleases me! It has some sort of short shifter in it, but I am going to put the GT350R shifter in it because I prefer that shifter over this one. And eventually the GT350R steering wheel.

 

[BmacIL]

I just ordered the Steeda clutch spring and the full kit for the trans and diff. Hopefully this pleases me! It has some sort of short shifter in it, but I am going to put the GT350R shifter in it because I prefer that shifter over this one. And eventually the GT350R steering wheel.

The BG trans fluid helps a lot, but the biggest improvement to shifting is a different shifter. I couldn't go back to stock from my MGW. The clutch spring change is a big improvement in driving smoothly, because you can actually feel the clutch bite point. Night and day there.

 

[Nickel]

The BG trans fluid helps a lot, but the biggest improvement to shifting is a different shifter. I couldn't go back to stock from my MGW. The clutch spring change is a big improvement in driving smoothly, because you can actually feel the clutch bite point. Night and day there.

My 2017 with 4k miles felt beautiful when I shifted and I was able to shift it very quickly, I'm hoping this one is being stubborn because of old fluid. I did just find out that I still have a drivetrain warranty with Ford so I might take it to service before I put really fluid in it in case they decide to drain it. Thanks for everyone's help.

 

[DickR]

Hello all. My 2016 GTPP has some pretty stubborn shifting problems which my 2017 didn't have. It's just not very smooth in all gears. I bought this car with 16,700 miles and now it has over 17K. I've owned dozens of rear wheel drive cars and always do my own work. I plan to upgrade to the Steeda clutch spring and want to change out the fluids.

Going to do the BG Synchro Shift 2 kit with everything I need. I don't necessarily track my car, but I accelerate hard all of the time, and slide the car sometimes, and I also spend a lot of time on windy roads like Deal's Gap and 181 here in NC. With that being said, would it be smarter for me to go with the 75w140? I'm unsure whether or not I have the differential cooler.

Thanks!

Since you bought the car used how do you know that the shifting issues aren't due to transmission damage by the previous owner(s)?

 

[Nickel]

Since you bought the car used how do you know that the shifting issues aren't due to transmission damage by the previous owner(s)?

Definitely a possibility that I've considered, which is why I'm happy that it still has the drivetrain warranty. I think I'm going to take it to Ford before I do the fluid change in case they decide to drain the fluid. Might as well make use of the year I've got left on it for peace of mind.

 

[Nickel]

This is what it looks like though!

 

[fiveoboy01]

The fluid will help but as mentioned, a shifter makes a significant difference.

Of course this is assuming there's no internal damage or issues with excessive wear. It sounds like you beat the car quite a bit, so perhaps the issue is self-inflicted.

 

[Nickel]

The fluid will help but as mentioned, a shifter makes a significant difference.

Of course this is assuming there's no internal damage or issues with excessive wear. It sounds like you beat the car quite a bit, so perhaps the issue is self-inflicted.

I haven't had a chance to beat on it yet, but I'm generally pretty easy on the transmission. Never caused any failures in any other cars, that's for sure. If there IS a problem then I suspect it's from inexperienced test drivers and previous owners because I mentioned this on our test drive.

 

[fiveoboy01]

I haven't had a chance to beat on it yet, but I'm generally pretty easy on the transmission. Never caused any failures in any other cars, that's for sure. If there IS a problem then I suspect it's from inexperienced test drivers and previous owners because I mentioned this on our test drive.

I was going off your comments about always accelerating hard and sliding the car, but I misread your mileage numbers in my speed reading fury.. You've only put 300 miles on it. My mistake!

 

[JohnD]

I just ordered the Steeda clutch spring and the full kit for the trans and diff. Hopefully this pleases me! It has some sort of short shifter in it, but I am going to put the GT350R shifter in it because I prefer that shifter over this one. And eventually the GT350R steering wheel.

The GT350, including the R has a Tremec 3160 transmission. Can't see how that shifter would work on a Mustang GT with a Getrag MT82 gearbox, unless someone stuck a Tremec 3160 in it.

GT350 shifter: https://www.mgwshifters.com/shifters/mustangs/139

GT shifter: https://www.mgwshifters.com/shifters/mustangs/103

 

[Nickel]

The GT350, including the R has a Tremec 3160 transmission. Can't see how that shifter would work on a Mustang GT with a Getrag MT82 gearbox, unless someone stuck a Tremec 3160 in it.

I actually just meant the shift knob itself. And this company has corrected the thread in them for the S550.

https://www.cjponyparts.com/ford-sh...ed-accents-v6-ecoboost-gt-2015-2019/p/MSK409/

 

[abmobil]

I was debating on the differential fluid as well. At 8400 miles I put Amsoil Severe Gear 75w110 in as well as the BG fluid in the trans.

I can’t tell much of a difference with the BG fluid in the trans but my trans always felt pretty good.

I went with the Amsoil because I’m also aggressive at times, and just wanted that little extra as far as protection is concerned.

 

[Mikepol2]

My diff is at the shop getting 4.09's installed. Optimum Performance Mustang told me to use 75W140 because the 4.09's will produce more thermal load than the 3.73's - any opinions on that thought?

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