We have a 2017 4WD 2.3 EB Explorer. We intend to keep it 10+ years as we do all our vehicles. The PTU, Ford's new style transfer case, requires synthetic 75W-140 gear oil and the RDU, rear differential specs 80W-90 non synthetic gear oil. Both are Motorcraft gear oils and both are "Life Time" fills supposedly. From what I've seen the PTU can turn the Motorcraft synthetic 75W-140 into black cake in as little as 30,000 miles or less rendering the PTU unit useless and broken. For long term life I've always changed the rear diff in the past, at least by 30,000 miles with synthetic gear oil. I'm wondering whether Amsoil's Severe Gear 75W-140 for the PTU and 75w-90 gear oil would be more beneficial than the Motorcraft gear oils spec'd. For the rear diff I can use Amsoil 80W-90 synthetic gear oil also if the Severe Gear 75W-90 is not appropriate. Thanks!
Whimsey
Whimsey