2019 F-150 when to change gear oil

[MetalSlug]

75w90 + towing I don't know it good idea . I would still using 75w140 Mobil 1 and be done with it

 

[wpod]

I change the diff fluids between 1,000 and 5,000 miles on my vehicles. Transfer cases shed metals as well and only take about 2 qts and are easy to change.

 

[meep]

I used the amsoil severe gear in whatever is the 75-90 weight, and tow a travel trailer. The fluid which came out at 30k looked good and i saw no cause for alarm. Mine was weirdly low by my old school thinking, and I also filled it to the base of the fill hole. It’s been fine. I don’t see the extra half inch causing anything weird, such as more cavitation than is already there. 2018 f150. For what most of us do, unless there is a design issue with the diff, IMO I don’t see the need for a 140 weight.

i did the tcase also. Now, Ford calls for their ULV formula in the tcase. Amsoil calls for their LV equivalent, which is a tad thicker. I went with amsoil. The drain magnet was very clean, but I don’t 4x4 much.

 

[AutoMechanic]

I change it usually ever 20000 or so miles

 

[demarpaint]

I did the first service of the front and rear differentials, the ATF, and transfer case fluids @ 10K miles in my 2016 Wrangler.

 

[Tones]

If you follow your mileage computer, the diff and the transmission are the biggest source of reduction in mileage until they warm up. I see this in Houston, so it would be even worse in more severe climates. I certainly wouldn't use any heaver weight than required just as a feel-good measure. I recently changed mine with Mobil 1 75W-90 at 50k miles (should have done it sooner). I believe I'm seeing an increase in mileage. 30k is what I have traditionally used.