Our Ford F250 Super Duty manual recommends to service and change the differential gear oil after 150,000 miles! That's nuts! Oil is cheap insurance to keep your mechanical parts functioning properly.

I'd recommend changing your differential gear oil after 30-50k miles. Our truck has nearly 30k miles and the fluid was already getting dark. I HATE gear oil. It smells terrible and messy. But this job isn't difficult and provides an excellent opportunity to upgrade your differential cover! I'd recommend installing a beefy steel differential cover if you plan to drive off road. There's nothing worse than being stranded from a cracked or punctured differential cover.

We used Permatex Black sealant on the rear differential cover and gear oil was seeping after 6 months and we followed all the directions (1hr set before torque and 24hr before filling). Permatex Green is supposed to resolve the sealant breakdown issues. However, sealant is an absolute mess to clean up and time consuming. We decided to try the Lube Locker gaskets instead. They are spendy but may be worth the cost for quicker service and hopefully no more fluid seeping. Will keep you posted!

Parts we used for this project:
OX Front Locker (HD diff cover)
Under Cover Fabworks Sterling 10.5 steel differential cover
Lube Locker D60 Gasket : https://www.lubelocker.com/products/d...
Lube Locker Sterling 10.5 Gasket: https://www.lubelocker.com/products/f...
Amsoil Severe Gear 75w90 (4 QT) rear differential
Amsoil Severe Gear 80w90 (3 QT) front differential
Drill Wire Wheel
Parts Cleaner
Lots of shop towels

#truckcamper #superduty #overland