loud noise

[Bbrown57]

Hello I have a 1999 ford explorer all wheel drive sport, this problem has been going on for a while no check eng light so must be mechanical starting from a complete stop I hear a loud banging noise coming from the rear of the truck happens about ever 2 or 3 seconds during excelaration until I I hit about 40 mph the quitens down with just and occasional bump after 40 and ideas would greatly help not a rich man so will be doing the work myself.

 

[Turdle]

Take the rear drive shaft out and inspect the u joints. If they are loose and flopy replace them. Aso, grease the slip joint in the drive shaft.