I looked on mud and all of the threads are old and most everyone insists its the fan hitting the shroud. Which its not doing. My case when in 4low and in a high torque situation jumps out of low and kind of in-between 2low and 4low and the gears grind real bad like they are not meshing. I replaced the springs in the case and it seemed to work for over a year, now its doing it again. Im going to look at the boots on the shifter and see if they are stiff from age as suggested on mud. Anyone else experience this and if you did what was your fix? This is on an 86 fj60.