John deere 544 tranmission problems

I HAVE WHAT I THINK TO BE A 68 - 69 544 JOHN DEERE LOADER. WE KEPT ON LOSING REVERSE LAST WINTER AND OCCASIONALLY FORWARD. IT WOULD RUN FINE FOR HOURS AND JUST STOP MOVING USUALLY AFTER DUMPING A BUCKET OF SNOW.AFTER REVING IT UP AND MESSING WITH THE CONTROLS IT WOULD MOVE AGAIN FOR NO REASON. I REMOVED THE VALVE BODY AND HAD IT REBUILT LOCALLY AS IT WAS DIRTY AND SOMEWHAT JAMMED FROM CONTAMINATION. I INSTALLED THE VALVE AND THE SHIFTER WAS HARD TO MOVE ALONG WITH FORWARD WORKING OCCASIONALLY AND SOMETIMES RQUIRING A LOT OF THROTTLE TO MOVE.WE BROUGHT IT IN ONCE AGAIN AND CHECKED IT OUT. WHILE REVING IT UP IN OUR SHOP WE HEARD A LOUD BANG LIKE SOMETHING BROKE INTERNALLY. NO REVERSE SINCE ! I REMOVED THE VALVE BODY AGAIN AND CHECKED IT THOROUGHLY. OUTSIDE OF THE TRIMMER VALVE BEING WORE SLIGHTLY ON ONE SIDE EVERYTHING SEEMED OK. BEFORE PUTING IT BACK ON I NOTICED WHAT IS CALLED THE "VALVE STOP" TO BE IN THE WRONG PLACE. IT WAS ALOWING THE SPOOL TO GO BEYOND REVERSE AND BOTTOM OUT IN THE COVER. I PUT THE VALVE STOP IN THE ONLY PLACE IT FIT WHICH IS ABOUT CENTER OF THE THE SPOOL AND STOP IT IN THE REVERSE POSISTION WHEN THE SPOOL WAS PUSHED ALL THE WAY IN ACORDING TO THE DETENT PIC IN THE PARTS MANUAL. (ALSO WHERE THE FACTORY YELLOW PAINT TERMINATED ON THE SPOOL). FIRED IT UP AND WITH QUITE A BIT OF THROTTLE IT GOES FORWARD SOMETIMES,STILL NO REVERSE BUT EASY LEVER ACTION. OTHER TIMES IT MOVES FORWARD WITH ANYWHERE FROM 0 TO MINIMAL THROTTLE. STILL NO REVERSE AT ALL NO MATTER HOW HIGH THE RPM. IM HOPING THAT SOMEONE CAN TELL ME HOW TO DETERMINE IF THE TRANSMISSION,CHARGE PUMP, OR TORGUE CONVERTER IS TO BLAME. I CAN FIND NOTHING ONLINE AS TO WHERE AND WHAT PREASSURES TO CHECK. I AM STUMPPED. I REALLY DONT WANT TO PULL THE TRANSMISSION AS NO ONE DOES. ANY HELP WOULD BE APPRECIATED BIG TIME.:mad:

John deere 544 tranmission problems