1971 Ford 4500 Backhoe oil question

[pope]

Hi, I'm a new member and just purchased a '71 Ford 4500 backhoe. It has a 3 cylinder diesel. Looks like the previous owner didn't keep up on the maintenance. I want to change all the fluids & filters. Need to know the oil specs for this machine. I have heard that the motor uses one type of oil and all the other fluids use a different type but these are all the same. Not sure if this is true. What is the best motor oil to use? What is the hydraulic, tranny, rear-end, power steering to use?

Thanks for any help.
Mike