Tractor Repair: 1466 will not move, rear axles, clutch pedal

Question
Hello, I have an international 1466 that dont want to move. It shifts in and out of all gears with no problem and I can feel it engage, but when I let out the clutch It doesnt move, If I idle way down to 600-800 rpm it will move very slowly but only in 1st and second gear in low with the t/a on. I am thinking eithe the clutch or the hydraulic pump. Any help would be great thanks.

Answer
At least you know the transmission is turning if it creeps a little in low gear.  Normally, if a clutch is bad it slips under load and gradually gets worse, but it would have to be real bad to slip this easily.  First make sure the clutch pedal has at least an inch of free travel and adjust if necessary.  If it doesn't make a difference whether the TA lever is forward or back, then it probably isn't the TA.  Both high and low don't fail at the same time.  If the power steering still works, then the hydraulic pump is OK.  The same pump feeds the power steering, brakes, and TA.  Check that neither of the rear axles are turning inside the wheels.  I saved the best for last.  If everything else checks out OK, then possibly the differential has failed.  You can look through the rear cover above the pto where the center arm for the 3 pt. hitch attaches to the tractor.  Have someone run the tractor in gear and see if the differential is turning when the tractor is not moving.  If it is turning, the differential has failed.