If I remember correctly, they did this for me at 40k service and I think I need to do it again? Do I?

if so, please share any videos you mights have or any helpful tips to keep me from making beginner mistakes

 

It's easier than your brake job. Jack up and support the back end. Undo all the bolts, pry open the cover, be sure to have a pan ready to catch all the nasty fluid. Once all drained clean the cover, get some emery cloth and remove all the old gasket junk. Get a bottle of brake cleaner, clean the internals the best you can. Put blue gasket sealant around the cover and diff. Bolt and torque down all the bolts. Fill with required fluid and add a 4oz of diff additive. Done

 

 

Holy necro batman, this is an old thread.

 

If these are available for your truck, do your self a favor and use Lubelocker gaskets.
No messy RTV to deal with and if the cover bolts are torqued correctly, they're re-usable.

https://www.lubelocker.com/product-category/parts/

I changed the fluid last year on both the front and rear diff in my Jeep XJ using Lubelocker gaskets.
The worst part was digging out the past RTV from the thread holes and scraping it off the cover and diff.
No more RTV again, ever.
My Jeep's diff's covers are now as dry as they can be after a couple thou miles.
.

 

Personally I would not recommend spraying the inside of the differential with brake fluid. I would follow the procedure below by a great Ford mechanic.

 

Who cares. This thread might help someone else.

 

 

Serving suggestion:

https://www.harborfreight.com/oil-su...gun-95468.html

 

Isn't the correct answer "40,000 miles is too soon. You're wasting money". That's helpful.

The guy that resurrected the thread didn't even ask a question. Just made some statements.