I've got an 88 4runner and it's making a really bad screeching sound when I put it in reverse.

The sound only occurs when letting off the clutch (not when rolling with the clutch depressed)

The sound is not made when I jack up the rear end and let the tires spin in reverse. I have been getting a similar sound though not nearly as bad when I first let off the clutch in 1st gear also lately. I had someone listen as I reversed past them and they said the sound seemed like it was coming from the drive shaft towards the rear end. Any ideas of where to start? Thanks

 

Could be U joints.

 

What am I looking for to pinpoint the U-Joint, I thought that would give you vibration going down the road?