A strange clunk after service

[Off the Grid]

Great site and a wonderful knowledge base. Here's my situation. Self diagnosed and had a Ford dealership replace the front pinion seal. ($135 in Nor. CA) After driving away on the asphalt, I shifted in and out of 4WD several times. On several occasions, not every time, I heard a very loud clunk coming from rear differential. I returned and took a tech for a ride. He said, since it was close to closing I should probably bring it back but offered no guesses. He did say the sound may be more pronounced because we were driving on a hard surface instead of offroad. My Ranger is a 2003, 3.0 L with 66K miles on it. I drive in 4WD everyday up our 2 1/2 mile long driveway. The 4WD system has operated flawlessly up until this time.

Is it also true there are no grease fittings on this beast?

Thanks guys.

 

[97ranger4x4]

have you tried shifting in/out on the dirt? What were your results?

 

[Off the Grid]

What the heck

have you tried shifting in/out on the dirt? What were your results?

No noise when I shift on the dirt. I don't know what to make of it.