What about the early STX 4wd tractorsIJ I have an early one and I have had dealer look at it several times because of irratic take off when placed in gear. Sometimes baby but smooth or times feels like you side stepped a clutch. What do you think the problem isIJ I know we have changed a solenoid pack on the front of tranny, but really did not fix it and now I know it is out of warrantee.