the reel spins in a jerky fashion, somewhat like when the rollers get cloged with hay, no bangs or klunking sounds, and knife moves freely. just cleaned it all up today and re-greased it but it still moves in a hesitant, jerky kind of way, thought maybe the belt may be slipping or chain is out of time?? not sure where to look........... JH
Kubota L3830GST, B7500HST, BX2660. Formerly: Case 480F LL, David Brown 880UE
We have a NH479 and on that, I would look at all of the chains/belts on the left side while the PTO is spinning to see where things are binding up. It sounds almost like one of the bars on the reel is binding at one point and once past that point, the tension is released and it surges ahead. To test that, I would number the bars and see if it always happens when a specific one is in the same place.
IIRC, the reel is chain driven off of the gearbox, so unless it is jumping links, it is probbaly not the chain.
A parts diagram is available online from Messicks at http://www.messicks.com/NH/60600.aspx and they are pretty good to work with over the phone (that's how I diagnosed the problem with the overrunning clutch on our 479).