Well the other day I jacked up the front end and sat it on jack stands trying to be able to recreate it with the truck off and had no luck, couldn't find anything with play either

 

i had the same thing happen to my 2002... front end was tight, replaced the track bar bushing and got better, ended up replacing the bolt and self tightening nut on the axle side because they were striped hasnt done it since... try checking/ replacing the bolt and nut.. and make sure u have the bolt torqued down

 

My 2000 did that too, it was the track bar bolt and bushing on the axle side

 

Well tightened down the bolt on axle side side of track bar and the pop stopped? It wasn't even a 16th of a turn loose so idk but now its gone so guess that was it.

 

If it pops again replace the bolt and nut on the axle side.. They say the bolt should be torqued to 130ft lb

 

I had to order a new one (bolt and nut). Torqued it and checked it a week later had to retorque a quarter of a turn.