I live 45 minutes out of town and it's a pain to have to drive in for something I may need to change for rear diff fluid on my 99 F-150 4x5 5.4.
Is there anything I should be aware of or is it pretty much standard.
1) take rear plate off
2) drain old fluid good (Do you put the front end up to drain properly?)
3) clean contact surface good on plate and read diff.
4) silicone plate good.
5) put plate back on.
6) fill with new gear oil
(Recommend FORD gear fluid or other)
(I do not see a hole to fill on plate. Where is it?)

 

Paul64 not sure on a 99, but I have a 2005 stx. You pretty much have all the right steps. I di not put mine up in the front and was able to get all the old fluid out. They actually make a Gasket for mine and I'm pretty sure yours. I used Red line 75w140 synthetic in mine. 75W140 is recommended by ford. The fill plug on mine is on the drivers side front (facing the front of the truck) of the differential housing. Hope this helps.

 

You've got it down for the most part.

Make sure you use Synthetic 75W90
Friction Modifier if you have LS
3/8th ratchet and 1/2" Socket
Screwdriver and blade to peel off the cover and clean it,
and brake kleen or the likes to clean the cover

There is a fill plug at the left side (driver's side) of the differential facing forward. It's a 3/8ths inc square that you'll need to use the ratchet for. Remove that, clean off the metal flakes off the magnet and fill it.

You don't need to lift the front to get a good drain, just use some rags and your fingers. Get out as much as you can, but don't sweat it all.

Sounds like you've got a good handle on things, just don't over tighten the bolts (30-38ft/lbs).


Good luck with it!