2003 f150. What is good fluid to use. Is this something I can do in my driveway.

 

You can do the work in the driveway. I use Wal-Mart Supertech full synthetic 75W140 GL5, about eleven bucks a quart. The 8.8" differential requires 2-3/4 qts. If a limited slip, then some friction modifier is required which you can get at your local parts store.

Rig one of the quart container caps with a six-inch length of 3/8" tygon tubing to make getting the oil from the container and into the fill port a little easier. Clamp the tubing to the cap spout with a ty-wrap to keep the tubing in place.

When the differential is filled a crooked finger will find the oil about 0-1/2" below the port.

Have fun.

 

I usually just squirt until the fluid barely begins to run out of the fill port...that's how I do the transmission too.