Happens when I go from first to reverse or vice versa. It sounds like slack somewhere, I've checked everything ring and pinion,control arms,shocks and brakes. Replaced the already worn out at 20000 miles driveshaft, still pops once when I pull out. I noticed the pin rocked somewhat on the carrier? Anybody else been here?

 

Lifted 3'' with currie arms and 4.88s. Even with the diff cover removed the only play is in the pin for the spiders. I've had far more in my past Jeeps without hearing it.

 

No, it will only make the sound once when I change direction from first to reverse or reverse to first. After that I can dump the clutch gas it whatever and it still wont make the sound till I change direction.

 

Without being there, it's tough to make a good diagnosis, but judging from your description you have described classic U-joint noise. Are your U-joints greasable? If so, then that may solve your problem if they're not too far gone. Also, how high is your Jeep idling? An idle that's too high will make any driveline pop and clank when engaging a gear.

 

Thanks all for the help, finally found rocking rear brake calipers. Should be crawlin in dried up creeks anyway.