Mowing 488 NH Haybine Belt Replacement?

[CountryCowgirl]

I need to change the belt on my haybine and can't seem to do it. It is the belt that attaches to the wobble pulley at the bottom and the conditioner pulley at the top near the gears. I can pull apart the wobble to get the belt off there but how do I disconnect the gear box to get the belt off ? Any help would be greatly appreciated as we do not have an onsite mechanic right now and need to change this belt so we can cut our hay! Thank you

 

[steve08]

I would have thought that kind of info. would have been in the Manual...

Ya might try Askin over at 'Yesterdays tractor' or a Site called 'Hay talk'

Best of luck to Ya!

 

[zzvyb6]

On the underside of the mower, just behind the crusher rolls, is a caged bearing that must be unbolted. Then you can pull out the gearbox along with the cross shaft and get the old belt off and the new one on. While you are at it, inspect this bearing to see if it ought to be replaced (new one at TSC). Also examine the chains carefully to see if they are stretched or shot.

If your mower has the pin clutch, be careful when pulling the driveline away from the mower side because the springs and pins can and will fly away.

Other than that, its pretty straight foreward.

If the bearing is shot, just cut it off instead of wasting time trying to soak it, or hammer it or pulling it off the shaft. Just cut it open with a die grinder or a cold chisel. The new one will just slip on and has an eccentric collar that tightens it to the shaft. Do THAT when the gearbox is all fastened down so the bearing won't have any preloads on it.

 

[mike10]

The procedure should be in your operators manual. In case you do not have a manual here are the steps.

Remove the shield over the slip clutch, Remove the set screw holding the slip clutch to the gearbox shaft. Tap the slip clutch of the gearbox shaft. Remove the two roll drive chains. Go under the back of the haybine and look up to your left right behind the top roll and you will see a bearing and collar. Remove the center three 3/8" bolts that hold the bearing flange to the plate. You do not need to remove the bearing unless it is bad. You only need to remove the bolts holding the bearing flange. If you have not yet done it loosen the drive belt. Remove the knife bolt from the wobble arm. At the bottom of the wobble box are three 1/2" bolts that come from the bottom up. Remove these three bolts. These bolts go into the lower bearing plate on the wobble arm. You will see that there is also a spacer plate between the wobble frame and the plate the three bolts went into. Remove this spacer plate. Now you can rotate the lower plate 180 degrees. Take the belt off the top pulley. Now you have enough slack in the belt to remove it from the wobble box. Now that the belt is free at the bottom, remove the 3/8" bolts that hold the gearbox side plate to the side of the machine. Once these bolts are removed you can pull the gearbox and side plate away from the machine a couple of inches and you can remove the belt through this opening and over the gearbox. Installation is just the opposite steps.

 

[BeeferMan]

If this seems like a really poor design, I won't argue with you. This is a nasty job the first time you do it, seems like a lot of work to change a belt.

The second time is a lot easier though, especially if you've used plenty of never-seize on that bearing up and behind the rollers. I've never been able to salvage one of those bearings that hasn't been installed with lots of never-seize/grease, I always end up cutting it off with the torch and replacing it. If you cut off just the outer race you can then pull the shaft through the housing and get the inner race off where you have much better access.

While you got it apart it's a good time to check the wobble box bearings thoroughly.

 

[Kater]

Mike, I've already got the belt past the gear box (previous owner had a spare belt partially in place) so I just need to navigate the wobble arm assembly. Are the instructions the same for a NH 460?

 

[Kater]

The answer to my question is "yes"; it works the same way on the 460. Just wish I had known that the "spacer plate" was that incredibly thin piece of metal and that the 180 degree rotation was up (not lateral)!