I've been chasing a loud clunk for about 2,000 miles +/- that would shake my 2-door 18' JK, intermittently. Mostly when coasting or braking down a hill. It's a pavement queen that's lifted 2" and on 35's, how original 
. I swapped out the carriers to Truetracs and gears to 4.56.
I've spent hours troubleshooting yet I was able to isolate the noise to the rear drivetrain by removing the front driveshaft then the front carrier/axle shafts (yes, I put a 3/4" bolt through the unit bearing although not needed). I thought the rear carrier was loose but everything was within spec. I noticed a bit of play with the axle shafts so I rebuilt both (16,000 miles) with new bearings & seals. I was set on believing I had a defective Truetrac until I broke down, joined the 21st century, and purchased a GoPro with a magnetic mount. Turns out, it's my driveshaft and I'm glad I caught it before it did any further, serious damage.
You can really see & hear it past 1:50
On a lift (2 post), there was no obvious sign of failure. Even when I disconnected it at the axle, it spun freely and the boot is in tact. No grease deposits, nothing. This is a Jeep with a 2" lift that has never been wheeled. It makes sense diagnosing the issue as the weight of the vehicle shifts forward upon coasting or braking resulting in slightly greater driveshaft angles. This coupled with forces counteracting between engine braking & axle rotation/braking definitely twists the joint.
. I swapped out the carriers to Truetracs and gears to 4.56.I've spent hours troubleshooting yet I was able to isolate the noise to the rear drivetrain by removing the front driveshaft then the front carrier/axle shafts (yes, I put a 3/4" bolt through the unit bearing although not needed). I thought the rear carrier was loose but everything was within spec. I noticed a bit of play with the axle shafts so I rebuilt both (16,000 miles) with new bearings & seals. I was set on believing I had a defective Truetrac until I broke down, joined the 21st century, and purchased a GoPro with a magnetic mount. Turns out, it's my driveshaft and I'm glad I caught it before it did any further, serious damage.
You can really see & hear it past 1:50
On a lift (2 post), there was no obvious sign of failure. Even when I disconnected it at the axle, it spun freely and the boot is in tact. No grease deposits, nothing. This is a Jeep with a 2" lift that has never been wheeled. It makes sense diagnosing the issue as the weight of the vehicle shifts forward upon coasting or braking resulting in slightly greater driveshaft angles. This coupled with forces counteracting between engine braking & axle rotation/braking definitely twists the joint.
