case 580 SE backhoe. arm wont swing fully right?

the backhoe arm will not swing right as far as it should stops hard about 2 foot short of where it should.. arm goes fully left. smooth the whole way until it stops. replaced upper and lower pins.. and new right swing cylinder. new hoses. if you take the pin on the end of the left swing rod out the arm will make it fully right as it should? is it a dead left swing cylinder holding it back? what confused me is I took the top pin out at the beginning it was wore down. looks like nobody knew what grease was. flipped it 180 degrees around to where the lock nut hole was pointed backwards towards the operator.. knocked it back in and the thing swung right like it should? thought the pins were throwing it off or something but after new upper and lower pins back to square one! the man who owns it says he didn't notice it until after he changed the hoses.. they are all clear and not collapsed. hooked up right according to the manual..and the right swing cylinder was replaced because the rod had a bend in it. clearly visible. what woulda caused that? hydro locking can bend them I know. any help appreciated ive been in diesel mechanic school for 5 months now so just trying to learn all I can.. can fix anything just don't have the diagnosing part down yet haha