I THINK it was a 1411 that I bought. Bought it back in 94,was supposed to be 2 years old,was traded in on a new Hesston 12 foot hydraswing disc type. That was a while ago,so my memory about the number on it is foggy.
Regardless,I had the same problem. I used it for about an hour and a half and it was making so much noise I couldn't run it anymore. I took it back,they took it apart and said there was a bearing out in the shaft that goes down from the PTO gearbox to the cutterbar. Said it tore up the shaft,they'd fix it,no charge. Got it back 10 days later,used it five times,it got louder every time. Finally went to crap. I could turn the disc on the outside end and it would turn all of them but the first one on the inside. Apparently the gears were torn up in the cutterbar too. I ended up with a new Hesston conventional for what I'd paid for that one,even trade. I've got no interest in ever having another New Holland discbine. Hesston maybe.