Just in the rear-end. The PTU is a whole other story and should be done every 30k max.You can use 75w90 synthetic with no problem, and probably never have to change it again
They learned their lesson over the years with the FWD PTU units. Originally they had no drain plug, only a fill. Later, after they all started burning up, they added a drain. Now they have Drain and Fill, and have air ducted to them from under the car. I believe they hold more fluid now as well. Originally it was under a quart, as I recall it is almost 2 quarts now. They also went from 'filled for life' to 'this needs service', I suspect that was when the drain plug was added.I have a 2017 2.3EB Explorer. I've been using Amsoil 75W-140 Severe Gear in the PTU and their 75W-90 SVG in the rear diff. The PTU was changed multiple times early in it's life. The last change was at 24,500 mi of use and the fluid came out clean and there was really nothing on the magnet. The rear diff was Mity Vac'd out at 22,500 mi originally and next at 69,000 mi on the vehicle. Like your Fusion the Explorer is mainly FWD so the rear diff is not used as much, I assume. I would expect any quality brand synthetic gear oil changed at the ~30,000 mi intervals in the PTU would hold up fine. Ford's idea of it being a "Lifetime Fill" is a poor joke on the vehicle owners.
Our 2017 has a drain plug thankfully and being a 4 cyl there is no where the degree of heat as from the V-6. Our PTU holds 24 oz instead of the 18 oz the V-6's held and is easy to change. Interestingly our 2.3 EB does not have a engine under belly pan, it's wide open like in the old days. Our 2017 PTU was still listed as a "lifetime" fill.They learned their lesson over the years with the FWD PTU units. Originally they had no drain plug, only a fill. Later, after they all started burning up, they added a drain. Now they have Drain and Fill, and have air ducted to them from under the car. I believe they hold more fluid now as well. Originally it was under a quart, as I recall it is almost 2 quarts now. They also went from 'filled for life' to 'this needs service', I suspect that was when the drain plug was added.
It holds slightly more than a quart, so you got about half of it out. What did you use to remove the rear diff fluid?Did the rear end the other day, got and 600 ml out and filled it back up... Oil wasn't that bad coming out, not much on the magnet so I guess it's wearing really well!
Had it on ramps and used a vacuum extractor... Tried to get more but that was it.It holds slightly more than a quart, so you got about half of it out. What did you use to remove the rear diff fluid?