Pop andjerk in driveline?

[4ever4d]

I have a 97 explorer xlt with 4.0 5r55 tranny and bw4405 transfer case at cruise and acceleration there is a pop and jerk in the driveline engine is running smooth so not a missfire any ideas what it could be everything seems to be solid ujoints,axles and driveshafts no fluid leaks just can't figure what it is.

 

[safn1949]

U joint would be my guess,my 2000 looked good but when it went on the lift and you could turn the shaft it was falling apart.Quite the vibration.

 

[4ever4d]

That thought crossed my mind, the pop or more of a thud sounds as though it's coming from the rear will replace ujoint and hopefully that will be the fix, easy and cheap.