I have a friend who just picked up a WJ limited (99 4.7, QD, 247)
Shop told her she didnt have any fluid in the TC, so they filled it. Right after they filled it, it started making these noises.
I drove it yesterday and its a ratcheting that increases with speed. Definately metal on metal. The output seals are leaking bad, so I assume she ran it dry.
One other note here is I found some gravel and attempted to engage the PC. All that happened was a terrible grinding sound from the TC. The ratcheting can be heard even when the TC is in N (and vehicle is moving)
Is this the Sun gears (shops theory), or Progressive coupler, or complete rebuild?
She got a $800 quote for rebuild.. I'm think half that for a j-yard install that I can do for her.