I have a 58B diesel with a shuttle and 1th 2nd and 3rd work well but 4th gear won't hardly pull it self up a small incline, I was told that means the torque convert is going bad, could it be anything else? I just use it around the farm a couple times a year.
If your backhoe will spin the tires in first gear, work well in 2nd gear, 3rd pulls farely well, 4th is a high end gear that is for roading and most will have trouble starting on a hill to move. Due to the age, engine, all i would due is a fuel filter change and check the air cleaner and run it. There are several posts here where members have gone into these older machines, they can be a pain real quick once you open them up. 4th is a road only gear and i would not try to start off on a incline at all unless going done hill.
I second that one, even after running wide open in 4th, when i show it a hill, I have to downshift to 3rd just to climb it Mines a 73 580B CK.
I'm with sheepfoot on this...I have a 68 580B and run it every weekend...gears 1-3 are great and only use 4th when I am headed down the road to the neighbors house.