La Ramie
Member
So my 2013 4x4 comes with 3.55 rear axle w/o limited slip.
Looking at 2013 owner's manual, the fluid for the rear axle should be 75w-140.
But looking at 2022 Classic owner's manual, the 3.55 uses 75w-90, and 75w-140 should be for 3.92.
That's a big difference in viscosity between 75w-90 and 75w-140.
Since the front axle uses 75w-85, it would make sense for the rear to use also 75w-90. This way I can buy the oil in boxes, which is cheaper. Yes, 75w-85 and 75w-90 are interchangeable.
Did Ram change the rear axle?
I know the transfer case was changed after the change to 8hp from 65rfe but I wasn't sure about the rear axle.
Looking at 2013 owner's manual, the fluid for the rear axle should be 75w-140.
But looking at 2022 Classic owner's manual, the 3.55 uses 75w-90, and 75w-140 should be for 3.92.
That's a big difference in viscosity between 75w-90 and 75w-140.
Since the front axle uses 75w-85, it would make sense for the rear to use also 75w-90. This way I can buy the oil in boxes, which is cheaper. Yes, 75w-85 and 75w-90 are interchangeable.
Did Ram change the rear axle?
I know the transfer case was changed after the change to 8hp from 65rfe but I wasn't sure about the rear axle.