i have a 1980 model kubota L285, pto works and engages properly , but when you put trans in gear it will move but very slowly , even in higher gears really slow . i tried pulling a disk when i first got the tractor , it wouldnt pull , and i heard a grind in the trans area , how should i proceed and what should i be looking for . i pulled a finish mower yesterday , mower turned fine , tractor didn't move real fast but i heard no noice . as you can tell im fairly new to working on tractors...