Need help identifying these parts

[Tangoddess]

Hello and good morning,

We bought a used New Holland tractor, I believe it is a NH 3930. This is my first tractor, so I am a COMPLETE newbie to tractor ownership

I believe this part is broken, and I need to replace it.

Does anyone know what it is, and what part number I need to replace it with?

Is it a standard size? and can I order it online or do I need to go to the dealer or a Tractor supply/

Second, I got a bolt stuck somewhere in the PTO mechanism or the attachment mechanism....see the photo.

Can I just hammer/drill the bolt out? It was a replacement bolt I got for the PTO as the earlier one broke, and now this one got stuck

Any advice on how to go about these part repairs etc. please

It is VERY appreciated.

thank you kind people

 

[Steave]

First picture is called an adjustable top link. Sometimes called a 3 point hitch top link. You can get them at most tractor supply stores. They come in different sizes so you will need to do some research on what size you need. I'm guessing your tractor would be a category 1 hitch and you can measure to get the length you need. These are adjustable but from the pix it appears yours is not adjustable anymore.

That broke bolt needs to be hammered out. Is that part of the bolt that holds the yoke onto the mower. If so you need to check and make sure your drive shaft is sliding in and out properly and it also may be too long. When installed properly the drive shaft should have at least a couple of inches of sliding room before it bottoms out.

Here's a link to the parts lingo: http://www.tractorbynet.com/forums/...6-three-point-hitch-lingo-5-123320-3point-gif

 

[Tangoddess]

@Steave

THANK YOU!!!

Can you clarify what you mean by "these are jot adjustable anymore" is that because it is broken....or is it because of some other issue/fixture on the machine?

thank you kind people

 

[Citydude]

It looks to be worn out. The top link is supposed to be adjustable and are not expensive to replace.

 

[3Lfarms]

It looks to me like the rod end closest to the implement is screwed all the way in, while the tractor side is screwed all the way out. Essentially the top link is just a big turnbuckle. One end has right hand threads and has left hand threads on the other. When the middle part is turned one direction, both ends should extend, and it should get shorter when turned the other direction. I think someone cheated and screwed the one end instead of adjusting it correctly.
You need to remove it from the tractor and screw both ends in as far as they will go by hand (lube the threads with oil first). Then connect the one end back onto the tractor. Then while holding the other rod end from turning, turn the middle part of the turnbuckle to extend both ends the same amount until it lines back up with the top hole on the implement. Then you should be able to fine tune the top link link it's supposed to work.

 

[Steave]

@Steave

THANK YOU!!!

Can you clarify what you mean by "these are jot adjustable anymore" is that because it is broken....or is it because of some other issue/fixture on the machine?

thank you kind people

The top link that's installed on your tractor now appears to not be working properly. As stated by others it is suppose to be adjustable in length. A new one will be adjustable and allow you to set up your implements.

If you are completely new to tractors this may be confusing at first but plenty of good information about the set up of implements on your new tractor can be had by searching online and asking questions on TBN. Good folks on here can surely help you if they run across your question.

Nice tractor by the way. Newer and larger than mine and built to last many years.

 

[Ford850]

Turn the shaft until the bolt can be accessed and driven out. Then pull the shaft back away from the mower gearbox and align the hole I marked with an arrow with the hole that had the bolt. Insert a new bolt that fits the hole (probably 1/2") and add a nylon or similar locknut so it doesn't vibrate loose. That's the shear pin, designed to break under shock, to protect the tractor and mower.

 

[aczlan]

Turn the shaft until the bolt can be accessed and driven out. Then pull the shaft back away from the mower gearbox and align the hole I marked with an arrow with the hole that had the bolt. Insert a new bolt that fits the hole (probably 1/2") and add a nylon or similar locknut so it doesn't vibrate loose. That's the shear pin, designed to break under shock, to protect the tractor and mower.

And make sure to use the right grade bolt. Too hard and you will break the gearbox, too soft and it will smear and be hard to get out.

Aaron Z

 

[scdeerslayer]

It looks like that top link was possibly broken on the implement side and was welded in place. I don't see any levers for adjustment either.

 

[Tangoddess]

Hello and good evening,

I had a young mechanic come over, and he replaced the top link. We bought a new one from TSC. It was about $~50, CAT 2.

He also hammered the bolt out of the shaft, and we bought a new battery, which may have been in haste, oh well.

Now, the issue is that we bought several Grade 5 shear bolts, 3/8 inch I think, 3 inches, but they kept breaking soon after turning the PTO ON

We even put a nylon locknut on each bolt

Do I need to get grade 8 shear bolts?

Or how do I get this fixed. The mechanic left, but I can put the bolt on myself if I can get it fixed.

thank you kind people

 

[aczlan]

Hello and good evening,

I had a young mechanic come over, and he replaced the top link. We bought a new one from TSC. It was about $~50, CAT 2.

He also hammered the bolt out of the shaft, and we bought a new battery, which may have been in haste, oh well.

Now, the issue is that we bought several Grade 5 shear bolts, 3/8 inch I think, 3 inches, but they kept breaking soon after turning the PTO ON

We even put a nylon locknut on each bolt

Do I need to get grade 8 shear bolts?

What is the make and model of your mower? The manual should specify what size and grade bolt to use.

How fast was the engine going when you turned the PTO on? It should be just above idle (around 1500RPMs), if you are much faster than that, the shock load from turning the PTO on can break the shear bolts.

Aaron Z

 

[jimmysisson]

And if the bolt is too small diameter the slop will help shear it upon engagement. Got a manual?
Jim

 

[Tangoddess]

Hello and good afternoon,

The model of the mower/brush hog is JOHN DEERE 513.

I could not find a manual online unfortunately, unless one of you has one?

I tried a 7/16th size bolt, that fit...about 3 inches, but I am not sure if I need grade 5, grade 8, or grade 2?

Do I need it to specifically say shear bolt, or can I get any bolt?

I really want to get this mower going

thank you!!

 

[Tangoddess]

Hello and good evening,

I found a reference to a similar issue here on TBN and found the following solution:

"Doc ID: WX53287

Solution Summary: Shear Bolt Fails Easily on 413/513 and LX4/LX5 Rotary Cutters

Publication Date: Jul 12 2002



Complaint or Symptom:

Shear bolt fails easily.

Problem or Situation:

Tractor PTO engages too aggressively, PTO cannot be modulated, or material being cut is too dense and heavy. This may too much stress to be placed on shear bolt causing failure. The 19M7329 repair bolt may not be strong enough when any of these conditions exist.

Solution:

Install 19M7479 Grade 8.8 bolt that has a longer shank. If application is still too heavy, a 19M8081 Grade 10.9 may be tried but care should be taken. Increasing shear strength of bolt may result in other damage to the driveline if due care is not practiced. The best solution is to install a clutch protected driveline. "

Is this 19M7479 Grade 8.8 bolt something I can only get from JD? It seems like it is $8 a bolt!

Or can I get an equivalent somewhere?

Thank you!!

 

[aczlan]

Hello and good evening,

I found a reference to a similar issue here on TBN and found the following solution:

"Doc ID: WX53287

Solution Summary: Shear Bolt Fails Easily on 413/513 and LX4/LX5 Rotary Cutters

Publication Date: Jul 12 2002



Complaint or Symptom:

Shear bolt fails easily.

Problem or Situation:

Tractor PTO engages too aggressively, PTO cannot be modulated, or material being cut is too dense and heavy. This may too much stress to be placed on shear bolt causing failure. The 19M7329 repair bolt may not be strong enough when any of these conditions exist.

Solution:

Install 19M7479 Grade 8.8 bolt that has a longer shank. If application is still too heavy, a 19M8081 Grade 10.9 may be tried but care should be taken. Increasing shear strength of bolt may result in other damage to the driveline if due care is not practiced. The best solution is to install a clutch protected driveline. "

Is this 19M7479 Grade 8.8 bolt something I can only get from JD? It seems like it is $8 a bolt!

Or can I get an equivalent somewhere?

Thank you!!

Grade 8.8 is a metric bolt, roughly equivalent to a Grade 5 bolt. Grade 10.9 is roughly equivalent to a Grade 8 bolt.
Hit your local hardware store and find one, it should be a snug fit and the unthreaded "shoulder" should stop just before the bolt comes out the other side of the shaft. That was it has to shear through the "shoulder" on both sides and not the "shoulder" on one side and the threads on the other.

Aaron Z

 

[Tangoddess]

hello @aczlan

Thank you!!

So can you or someone else explain which is the unthreaded shoulder?

Maybe this image below helps?

Thank you

 

[tcreeley]

hello @aczlan

Thank you!!

So can you or someone else explain which is the unthreaded shoulder?

Maybe this image below helps?

Thank you

HU and TU is designed to shear (undercut). The shoulder center of the bold remains in place when either end shears. The threads are just to hold the bolt tight with the use of the nut. They are not part of the shearing mechanism.



Shear bolts are designed with specific lengths in mind. I would think twice before substituting regular bolts that are not designed to shear, even of the same grade. - But then we all take shortcuts, and sometimes it works, or doesn't.

Research slip clutches - might consider working one of those in, more costly than just a shear bolt.

This bolt has an un-threaded shoulder and the a threaded portion for the nut.
This is a shear bolt with the undercuts in the unthreaded shoulder for shearing.