Case 555 9' pull type windrower

[CircleJFarm]

Anyone have any experience with this type of hay mower? I just purchased an old one and it is making a knocking noise at the wobble ball joint. It has a pitman arm which attaches to the cutter bar. Not sure if there is an adjustment or how difficult it is to replace. Any knowledge let me know.

Thankshttps://webparts.pvassociates.net/cnh/main.php