NH256 Operation

[mml373]

On my NH256 rake (new to me last fall), I notice that when I pull the unit behind the tractor I am getting one good spin of the tine bars, then it coats the rest of the revolution (of the spider, I think), then another good push, etc. It isn't continuously being propelled by the gearbox as it's moving forward with the tractor. Is this normal operation...what might not engaging?

I did have to wire the switch to engage the gearbox back.

Wondering if it is time to have the gearbox rebuilt or if this may be something else. I did replace the dogs in each hub last fall. From the sounds of things, they're working (when the rake is being backed up). Thanks in advance for helpful replies.

 

[flying belgian]

On my NH256 rake (new to me last fall), I notice that when I pull the unit behind the tractor I am getting one good spin of the tine bars, then it coats the rest of the revolution (of the spider, I think), then another good push, etc. It isn't always being propelled by the gearbox. Is this normal operation?

I did have to wire the switch to engage the gearbox back.

Wondering if it is time to have the gearbox rebuilt. Thanks in advance for helpful replies.

I know those rakes inside out and up side down but I just can't follow along your question.

 

[paul]

So it is spinning at uneven speed, fast for half a revolution, slow for half a revolution? Or some such?

Shouldn’t be that way.

Is a tire slipping. One dog weaker engaging and the other wheel slipping is common.

Is the wheel to gearbox shaft slipping square inside square? They do wear ‘not square’ over time.

Is a pin on either side of that square shaft sheared off and slipping on the shaft, the broken pin catches from time to time? More so on the wheel axle side.

Could be in the gearbox, but I would think something really bad would have happened in not too long of a time, gearboxes are not forgiving…. For me anyhow.

Random thoughts.

Paul

 

[Destroked 450]

I’ve had them spin up and over run the dogs in the hubs, as they coast down the hubs would catchup and sudden jerk would spin the reel again
This was usually when first starting off, but it should not do that with the gear box disengaged
Are you sure the lever is disengaging the reel from the drive shaft
When towing on the road for any distance it’s best to disconnect the square drive from the axle and tie it up

 

[495man]

Are you just pulling it around the yard to see this....or does it do it in hay?

Seems to me my 256 does something similar when starting, the rake tines freewheel a little faster since no load (hay) on the tines yet and the drive train catches up when they slow down.

Should work normal in hay.

 

[BarnyardEngineering]

Are you just pulling it around the yard to see this....or does it do it in hay?

Seems to me my 256 does something similar when starting, the rake tines freewheel a little faster since no load (hay) on the tines yet and the drive train catches up when they slow down.

Should work normal in hay.

This is exactly what I'm thinking.

Other than that, make sure the universal joints are timed correctly. If the yokes are 90 degrees off from each other on the ends of the driveshaft, it won't drive smoothly.

 

[mml373]

I know those rakes inside out and up side down but I just can't follow along your question.

When the rake is pulled forward by the tractor and the gearbox is engaged, then tine bars rotate but they do so as if there's only one "kick" each revolution, then they freewheel the rest of each revolution. Make better sense?

Are you just pulling it around the yard to see this....or does it do it in hay?

Seems to me my 256 does something similar when starting, the rake tines freewheel a little faster since no load (hay) on the tines yet and the drive train catches up when they slow down.

Should work normal in hay.

This is exactly what mine is doing. I appreciate this and other replies here and will diagnose and report back. May be awhile...all my equipment is heading out for various work, tomorrow.

 

[flying belgian]

When the rake is pulled forward by the tractor and the gearbox is engaged, then tine bars rotate but they do so as if there's only one "kick" each revolution, then they freewheel the rest of each revolution. Make better sense?

This is exactly what mine is doing. I appreciate this and other replies here and will diagnose and report back. May be awhile...all my equipment is heading out for various work, tomorrow.

the hubs must be packed completely full of grease not letting the dogs engage. Seems odd that it would happen to both hubs.

 

[mml373]

the hubs must be packed completely full of grease not letting the dogs engage. Seems odd that it would happen to both hubs.

I cleaned out all the gunk from the rake last fall (it had been sitting for years). It did work last fall before cleaning.

I left only light grease in the hub after cleaning and replacing dogs. Used a finger to lightly spread grease on the surfaces only. I wonder if the springs are weak on those dogs.

 

[flying belgian]

I cleaned out all the gunk from the rake last fall (it had been sitting for years). It did work last fall before cleaning.

I left only light grease in the hub after cleaning and replacing dogs. Used a finger to lightly spread grease on the surfaces only. I wonder if the springs are weak on those dogs.

Jack the wheel up and turn it backword. Can you hear it going click, click, click?

 

[mml373]

Jack the wheel up and turn it backword. Can you hear it going click, click, click?

I backed the tractor up and, yes, I did hear the dogs clicking...although I believe it was mostly the right side I heard. I'll check the left side tomorrow on a jack.

 

[flying belgian]

When you drive and stop abruptly does the bars keep spinning?

 

[BarnyardEngineering]

I backed the tractor up and, yes, I did hear the dogs clicking...although I believe it was mostly the right side I heard. I'll check the left side tomorrow on a jack.

You can rotate the bars by hand with the gearbox engaged, and it will rotate the shafts. That way you don't have to be up on the tractor guessing at what is going on.

I use this trick to grease the U-joints.

Are the bars severely out of balance? When you disconnect the gearbox, does the same bar always fall to the bottom?

Does the rake turn smoothly by hand all the way around? Does it rub hard on the stripper bars at any point?

I just can't see how this would be a gearbox problem. It would start-stop, not sling-coast.

 

[mml373]

I jacked the left wheel up off the ground and spun it by hand. I think the lever to engage the drive mechanism was not pulling back all the way. I took some hay baling wire and tied it back...will reevaluate when my tractor and tiller get home and will post back here.

 

[BarnyardEngineering]

I jacked the left wheel up off the ground and spun it by hand. I think the lever to engage the drive mechanism was not pulling back all the way. I took some hay baling wire and tied it back...will reevaluate when my tractor and tiller get home and will post back here.

The latch is an all-or-nothing thing. It won't engage partway around as you describe without making a lot of noise.

It's either how you're pulling it or the bars are badly out of balance with each other.

 

[will-max dairy]

The latch is an all-or-nothing thing. It won't engage partway around as you describe without making a lot of noise.

It's either how you're pulling it or the bars are badly out of balance with each other.

There are bearings on either end of the rake for the star wheels. There are also bearings on both ends of each tine bar. Any one of those bearings could have a bad spot that would create resistance to turning and then a kind of burst of motion when the resistance is overcome. Rare, but worth looking into.

What I haven't seen in the replies is whether the OP just tried to turn the rake over by hand with both wheels on the ground. Conditions like this (including the out-of-balance condition) should become apparent just by doing a couple of spins by hand.

Also, I wonder if the gears in the gearbox are fine, but I would imagine that there are "pinion bearings" on the input and output of the gearbox One of those bearings having a bad spot would do something like this as well. Seems as though, if either of the pinion bearings were that bad, the input or output would have some play in it (as in, if you just tried to wiggle the input shaft or the star wheel connected to the gear box... it would wiggle)... and with that much play... it would seem that the gearbox would be leaking lubricant like a sieve.

 

[NHbalerman]

On my NH256 rake (new to me last fall), I notice that when I pull the unit behind the tractor I am getting one good spin of the tine bars, then it coats the rest of the revolution (of the spider, I think), then another good push, etc. It isn't continuously being propelled by the gearbox as it's moving forward with the tractor. Is this normal operation...what might not engaging?

I did have to wire the switch to engage the gearbox back.

Wondering if it is time to have the gearbox rebuilt or if this may be something else. I did replace the dogs in each hub last fall. From the sounds of things, they're working (when the rake is being backed up). Thanks in advance for helpful replies.

Check the square shaft coming out of gearbox it could be worn down

 

[mml373]

Follow up to this...does anyone happen to know where to buy a kit to rebuild the gearbox? I'm thinking of taking that on as a project after this hay season.

 

[BarnyardEngineering]

Follow up to this...does anyone happen to know where to buy a kit to rebuild the gearbox? I'm thinking of taking that on as a project after this hay season.

New Holland dealer. Might not be a "kit" though, might have to purchase the parts individually. Not everything comes as a "kit."

 

[mml373]

True. I've seen the kits elsewhere and am dubious of quality, so my hope was someone may know of a good quality kit. The individual parts would be more expensive...sometimes that's an OK route but I just want to smarten up on options.