front popping/snapping sound
Okay, here's the down and dirty:
2000 GC Limited 4.7 QuadraDrive 89K. While on the interstate, we (my wife and I) heard a quick hissing/whizzing noise then the Jeep began popping and snapping (all throughout this whole venture, I have yet to get any "cluster warning lights like check engine, etc and no trouble codes). We babied her home. Took to dealership, they couldn't find any major problem, other than bad front prop shaft boot. Replaced front prop shaft with aftermarket that uses u-joints instead of CV boots. Just for good measure, replaced rear drive shaft u-joints as well (like to be proactive not reactive whenever possible). Took for test drive, still pops/snaps/clicks. Inspected front CV axles. Nothing wrong there, but replaced both (yes, I made sure to get the Varilock axles). Same result. Pulled, took back to parts store, got another set of axles, same result. Took to Firestone, they say bad transfer case. They came to conclusion without any diagnostic tools, just by test driving it on interstate for 1 mile, off the exit ramp and back on highway for 1 mile (checked mileage). Yes, I was there when she left the lot and returned. Are they for real? Anyway, nobody has been able to find this issue, or give good logical reason. Since I replaced the front prop shaft, I can now feel a vibration at lower speeds. All along, regardless of what I have done, the popping/snapping noise occurs when you accelerate quickly or get above 50mph.
Through testing, I have also noticed a few other anomalies. 1. If it put into 4LO, popping, snapping is immediate. 2. Hard left or right turns generate same noise. 3. Now that we have cold weather, popping, snapping at lower speeds for first few minutes, then only over 50mph. (but not when coasting) 4. Does not pop/snap over 50mph when not accelerating or on incline using throttle (does not do it when coasting). 5. Does not pop/snap if I remove front prop shaft (bad transfer case, front differential or axles?) 6. I am not crazy here, but the popping/snapping seems like it is rapidly alternating between left and right sides of vehicle.
I really need some help figuring this one out. Any suggestions are greatly appreciated.