When I bought mine at 250k, I had all the fluids replaced: oil, coolant, brake, blinker, trans, F/R diff and T-case. Now at 300k It's probably due for the diffs again. I don't run mine hard, and I exercise the 4x4 at least once a month for a few minutes. When I got it, I could hardly move the T-case lever into 4Lo, but after the change, It moves easily. There's a slight drag when slowly accelerating, and the best word I can describe it as is "gritty". Not like sand, but thicker viscosity than "smooth".