Hi, I have a 2007 Ford Ranger with the 8.8 differential (4.10 with limited slip) 28 spline.
Originally, Ford recommended 80w90 conventional gear oil (and 4 oz friction modifier for the clutches).
Now Ford recommends 75w140 full synthetic (and 4 oz friction modifier). They claim it supersedes 80w90.
Is this accurate or are they confusing the 28 spline differential with the 31 spline FX4 Level Ranger locker differential, which always took 75w140 full synthetic?
I’m planing on using Amsoil signature series and never changing it again, being that the truck is older now, anyways. Being that Amsoil is 100% synthetic and flows very good, maybe 75w140 would be fine?
I would go with the heavier one yes I do that all the time make some last longer
Thanks Scotty, I will then!
Get a hold of a Ford service tech manager and ask him.
