My truck started making a pop when in 4x4 and turning the wheels. I got a friend to stand outside the truck and locate where the popping is coming from, and he concluded it was the front drive shaft.......the one with the double cardan in it. Anyway, I removed it. All u-joints feel tight, but the splined section has a tiny bit of rotational slack to it. Is this joint supposed to be real tight, with the only movement being telescoping, or is a very small amount of rotational slack normal? Could this be causing the popping, or is it definitely my u-joints? I have the u-joints in hand, but since all joints "felt" tight, I wonder if something else is the culprit. Thanks in advance. By the way, the truck has almost 150k on it.

Waylan

 

That slack is wear and isnt supposed to be there. It can cause the noise you hear but I would check the Ujoints on the axle iteslf. My front shaft is worn like yours and I do not have any noise coming from it at almost 240k.

 

It's your front axle joints. Mine makes the same noise. they are expensive joints because they are so big.