tranny or Rear end problem
 

Yesterday will driving home I felt a slip and a hard jerk into gear will going about 25mph. After that I started hearing a griding noise like something was trying to go into gear (kinda like a 10speed between gears). It went away until I slowed down and started to accelerate again. The farther I drove the worse it got. Luckly I was less than a mile from the house and was able to drive slow to keep from getting worse.

This is in a 2002 F150 SuperCrew with a 4.6L and 168,000 miles.
vin FTRW07652KD75449 with no modification from stock except a remote start.

The noise sound to be coming from the middle of the truck so it is hard to pin point.

Makes the noise in Drive and Reverse, but not while coasting in Neutral.

Any Suggestions?

I don't think you should put your VIN number on the post...edit it. It sounds like a transmission problem to me.