Depending on the age of the loader you might find the manual on the JD web-site.
Operator's Manuals for John Deere Equipment
There are specs for the 520 and 540 loader. On some of the newer loaders 300CX have to dig a bit "Transporting a Round Bale". Granted this is not the level of detail I am guessing you are looking for, but it is something.
"What model are you wanting to know BTW"
I wanted to compare a whole raft of loaders with deere and kubota. Not sure how to research this one if the info is not available.