<font color="blue"> The dealer proposed that the shaft was caused from the 3pt being locked in the up position (set by the salesman that delivered the tractor) while using the backhoe. This caused "spiking" that could have broke the shaft. </font>
Something doesn't smell right here... /forums/images/graemlins/confused.gif
I don't know but would expect the hydraulic system to have a pressure relief valve for protection, and that if something was in the wrong position to cause system pressure to raise, the PRV should trip and offer protection.
Not a good thing for extended periods as it causes extra heating of the hyd. fluid, but where would "spiking" come from?
Something sounds wrong with what the dealer is saying...is he trying to push responsibility on you rather than repair under warrenty?
If they are repairing under warrenty and just speculating as to the cause that is one thing. If they are trying to get you to pay for the repair I would not accept that theory, and would suggest that it broke when it should not have and it should be fixed under warrenty.
Maybe the PRV valve itself failed and was not functioning, allowing system pressure to build excessively? Why do the loader cylinders need replaced? If they are bent, this could be another sign of system pressure being too high. This would cause excessive stress on the hyd. pump shaft and pump itself I would think.
Just a couple thoughts...