Many yrs ago I had a new one. First season had a knoter frame break. Replacement part was universal design and had to modify to work on the 336. Needle timing is pretty sensitive and instruction in owners manual was incorrect. Until a JD mechanic clued me in, lost 4-5 needles the first season. I did work the baler hard and as a result would loose the big-end crank bearing a couple times a season. Had to start carrying replacements with me while out on a job. To top that off, the bearing was a custom for JD. My dealer didn't carry just the bearing, had to buy bearing and carrier together. And on the early ones, the tongue jack was a real widow maker. Someone up above must have been watching over me as the jack handle just barely missed hitting me in the head when it went flying off the jack. That design was replaced after a couple seasons.
As you might guess, I wasn't a real fan of this baler. IMO the knoter on a MF 124 was way better design.