popping in drivetrain?

[997 xltawdshawn]

I have a well maintained 97 5.0 awd explorer with 193000 miles on it.
it's an automatic.
the cv axles have been replaced and the rack and pinion is in good shape according to the local shop. when I took it in I was noticing a popping noise when parking or backing out if the wheel is turned hard to the left or right. the shop said they thought the CV's might be binding up? that was over a month ago and I think it's getting worse. it's happening when I put the truck into reverse now which leads me to believe it's the u joints? any advice or suggestions will be very much appreciated. should I just lay under the truck and have my girlfriend put it in gear with her foot on the brake? I am completely unfamiliar with the drivetrain in this vehicle.

 

[toypaseo]

Clunk? Rear driveshaft slip-joint might need greased.

 

[Turdle]

This^^
If the popping continues, remove the front drive shaft and look it over real well for damage, wear at the transfer case end. The joint there is protected by a rubber boot which you cannot view well when it is installed, so you have to remove it.

Take it for a spin with the shaft removed. See if the noise goes away.
Beware, the front driveshaft is used to set the park pawl, so in the meantime carry a wheel chock to prevent the truck from rolling away if you need to park the vehicle before you can get the front driveshaft re installed.