What is ticking!

[Unsullied_Spy]

My Muggy did the same thing, it was the front diff. The gears looked perfect when I pulled it out but I replaced the ring and pinion then shimmed it and haven't had an issue since. Also double check all your drive cups to make sure the screws aren't coming loose. Locking it into RWD will help with find the problem but it will be very hard on the CD so make it quick and don't push it too hard!

[FG101C]

Are you running a plastic spur? Even if your not to me it really sounds like maybe the motor mount is flexing and the mesh is spreading? What does your spur and pinion look like? Seems like something is flexing, check everything for hairline cracks.