Art and Jim’s Machinery Shop
New Holland 479 Haybine Belt Change
During the winter months, one of things you may find time to do is check over your haybine. I use an older machine, a New Holland 479 Haybine (1972-1977). It is a good old machine and if the rollers are in decent shape can provide years of service with little work. I rebuilt one of mine it from the ground up in 2009, rebuilt a second machine in 2012, and will rebuild a third in 2017. I find them at auctions and can get them for just a few hundred dollars. My focus is are they straight and do not have holes rusted in them, which are usually found near the sickle where old hay was not removed and gets wet and damaged the sheet metal. I also examine that guards are present, good tires, and of course decent rollers. Belts are reasonably priced for this haybine…but the belt that goes around the wobble box, which drives the sickle bar is a bear, one of those engineering marvels where they did not quite think things through. That is why we have today’s model 488, New Holland needed to make a few adjustments to a darn good machine to make it better and a get questions from folks that contact me a lot about changing the that belt on a New Holland 479 Haybine.
So, if the belt is worn and you have some down time due to rain,winter break or you unfortunately have the belt break and have never replaced one before, I would like to share some steps that should help get you going again.
First things first, safety…frankly I have the haybine hooked to the hitch of the tractor and the wheels on everything chocked. Why, do I hook the haybine to the tractor and not just leave it to the haybine jack…well, as much as I like New Holland hay equipment, the jacks on the old 479 are not to be trusted with your life. With things hooked up and chocked I feel much safer when I climb under the machine to do the work. Always safety first!
Once you have all your tools together I would start by removing the shield over the slip clutch. Then remove the set screw that holds the slip clutch to the gearbox. Now remove the slip clutch assembly. The slip clutch assembly has always come loose fairly easily for me. However, a friend has told me that was not the case for him and he had to remove the eight bolts and springs, then remove the PTO drive shaft from the slip clutch. He strongly suggested you measure the spring length before removal so you can set the springs at the same tension as they were when you removed them. Sounds like good advice to me.
Now you get to crawl under the rear of the haybine and by following the gearbox output shaft you see a bearing up on your left. Remove the three (3) 3/8″ bolts holding the bearing to the plate. Now, when you look at that plate you will see four (4) 1/2″ nuts, DO NOT REMOVE THE FOUR (4) ½” NUTS…only remove the three (3) 3/8” nuts in the center of the plate. You do not need to remove anything else.
Now you move to the bolt and bushing that holds the sickle to the wobble box. Remove the sickle bolt, the bushing should stay in place. If it is tightened down and will not stay in place the sickle head is worn and will need to be replaced as well to keep you from wearing out bushings prematurely.
Now look under the wobble box. On the bottom side of the box you will see three (3) 1/2″ bolts. That go into the lower wobble box bearing mounting plate. Remove these three (3) bolts.
Under this mounting plate is a spacer. Remove the spacer. Rotate the mounting plate 180 degrees so the narrow end is pointing to the outside. Also remove the belt from the upper pulley to provide some maneuvering room. This should give you the slack needed to remove the belt from the wobble box pulley and work it out through the lower wobble box bearing mounting plate and support. It may take a little rotation so the box so the plate moves away from the mounting.
Now you can stand up and brush yourself off and remove the 3/8” bolts (a bunch of them) that hold the gearbox mounting plate to the side of the machine. Luckily you got to remove two of these when you removed the shield, but now the rest have to come out as well. Once you get all the bolts out you can pull the gearbox away from the machine, which may take a little wiggling to get the 2-3 inches you need to remove the belt from the top drive pulley.
Now slip the new belt through the opening and reinstall everything in reverse order.
The New Holland 479 is an old workhorse, but it will work just fine if the rollers are still in good shape and it is kept in the shed when not in use. The rollers hate the sun. Follow the greasing recommendations and always keep all the shields in place for safety. The pictures below are the before and after shots of the rebuilding and painting in 2009. Five years later and it has mowed over 2000 acres of grass, clover, and alfalfa. I replaced the wobble box bearings in 2012, and a few sickle bar bushings in the past five years. Other than that I have just replaced the usual blades and guards. The belts were replaced in 2009 during the rebuild and still look good. You have to like that. Enjoy your mowing and please… Always Be Safe!
I can also send a copy of the manual page to replace the belt in e-mail if that would be helpful, just contact me at HoosierHay@gmail.com.