Tractor Repair: Case 5250 Hydraulics, axial piston pump, clutch friction

Question
Start tractor cold and it growls, whines, for about 2-3 seconds and quiets down. Recently remotes are sticking on even warm and Hydraulic motor control sometimes would not stay on and constantly had to readjust flow control to maintain spray pump pressure. Also at cold start-up shuttle does not work  until about 30-50 seconds after starting, works fine after that. Drained oil and pulled screen and cover, found a fair amount of very thin pieces of crumbly dark clutch material, bronze-fiber in appearance, that sticks to a magnet? Machined pieces that are about .060 thick appears to be cast iron, and many pieces are large enough to show a radius(1/8 to 3/16 in size) There is some small pieces of metal, foil like pieces (shim)?, bright blue plastic(just a few tiny pieces). No dash lights showing. Oil temp never seemed high. Hydraulic filter was changed when I bought the tractor a few months ago. 5200 hours

Answer
  
  All machines that use pressure-flow compensated hydraulic systems make a growling noise at start up for a couple of seconds until the variable displacement axial piston pump builds low standby pressure.  Remotes that stick on are caused either by linkage pivots that rust tight by the remote valves, or by bad detent assemblies inside the remote valves.  Pressure gauges should be installed on the shuttle valve to check forward and reverse shuttle pressures.  There is also a safety spool inside the shuttle valve that prevents the tractor from moving until the clutch pedal is cycled after startup.  If the spool sticks or is slow to move, it could cause a delay in shuttle operation, or cause it not to work at all.  Changing flow from the remotes could be caused by an internal leak in the transmission or any of the regulated circuits.  It would be impossible for me to guess what the machined pieces are from that you found in the screen.  There is usually some clutch friction material, gasket sealant, paint chips, etc.  Blue plastic is probably teflon oil seals from inside the transmission.