4wd won't fully disengage

[dadman32]

2002 explorer won't fully disengage I push 4wd auto and I get a thumping sound and vibration, put it in 4wd high and it goes away but wants to pull to the left I go very far and the gear oil starts to get hot and smell any thoughts?

 

[Tyleryac]

Have you checked the transfer case fluid?

 

[dadman32]

Gonna do that first thing after work I was wondering/hoping that would be the problem