11. The last thing we did to the front of the truck was to mount an optional Extreme Ring over the differential cover. We installed ours without breaking the seal on the cover, though sometimes this procedure will cause a leak and you'll have to remove the cover and seal it back up with silicone. Designed to stand up to boulders, we know the Extreme ring will be more than capable of guarding our diff when we're blasting through snow or mud. Yes, we know the front axle is oily. That's the way the 7.3L diesel rolls.