# Do I need a stepped link pin?



## hd883chopper (Nov 12, 2018)

Hi folks,

Mainly use my old IH 364 for front end loader work but would like to use the 3 point soon. Bought the suggested top link and the 1” pin that connects it to the tractor. When I went to connect it to the tractor, the pin only would go through the left hole. The hole on the right was much smaller. 
Does this mean I need a stepped pin? Or should I use some sort of reducing sleeve on the left hole and use a smaller pin? I’m just very surprised that both of the holes aren’t the same diameter. Any thoughts or advice on how to handle? Thanks all!


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## Hoodoo Valley (Nov 14, 2006)

Your third link (upper link) won't hook up to where the upper (larger) pin is? That's a weird link hooked to it now.


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## FredM (Nov 18, 2015)

that setup has most likely got something to do with draft control when working tynes or plough, the linkage pivots on the top pin and most likely has linkages attached to a sensor of some type, most likely mechanical over hydraulic.

you have the 1" pin, why not have this machined to fit the small hole as in step, as you mentioned.

I am sure I have seen something like this in my past life, but just cant finger it.


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## pogobill (Jan 31, 2012)

I think you need a stepped pin like this parts diagram shows. #17
https://partstore.caseih.com/us/parts-search.html#epc::mr443417ar5354637bi1312485
They seem to be superseded by something else, but you can still find them on the net. You may be able to get away with a smaller pin and bushings that you could get at a Princess Auto for instance.


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## hd883chopper (Nov 12, 2018)

Hoodoo Valley said:


> Your third link (upper link) won't hook up to where the upper (larger) pin is? That's a weird link hooked to it now.


Would it be better to just replace the existing connection point on the tractor with one that has two 1” holes?


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## hd883chopper (Nov 12, 2018)

FredM said:


> that setup has most likely got something to do with draft control when working tynes or plough, the linkage pivots on the top pin and most likely has linkages attached to a sensor of some type, most likely mechanical over hydraulic.
> 
> you have the 1" pin, why not have this machined to fit the small hole as in step, as you mentioned.
> 
> I am sure I have seen something like this in my past life, but just cant finger it.


Thx Fred. I could have the pin machined down to fit. Before I did something like that I just curious if anyone has seen two different sized holes. I’m new to this so wasn’t sure what is customary. Thx!


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## hd883chopper (Nov 12, 2018)

pogobill said:


> I think you need a stepped pin like this parts diagram shows. #17
> https://partstore.caseih.com/us/parts-search.html#epc::mr443417ar5354637bi1312485
> They seem to be superseded by something else, but you can still find them on the net. You may be able to get away with a smaller pin and bushings that you could get at a Princess Auto for instance.


Thx pogobill, the sleeve with a smaller pin was my first thought but I wanted to get some opinions before doing that due to safety. I know they’re all large pins with lots of strength but was curious anyway. Tractor Supply didn’t have sleeves to fit the larger hole. If I go that route I’ll have to mic it for measurement I suppose. Thx!


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## Hoodoo Valley (Nov 14, 2006)

hd883chopper said:


> Would it be better to just replace the existing connection point on the tractor with one that has two 1” holes?


If you could find one, that could be an option. I'm just not sure how it would work with a standard third upper link.


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## hd883chopper (Nov 12, 2018)

Hoodoo Valley said:


> Your third link (upper link) won't hook up to where the upper (larger) pin is? That's a weird link hooked to it now.


This might be a silly question but could I just remove the existing pin, take that piece with the grease zerk out and the two hole fitting out? Then I could effectively use the existing pin and my top link.


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## FredM (Nov 18, 2015)

FredM said:


> that setup has most likely got something to do with draft control when working tynes or plough, the linkage pivots on the top pin and most likely has linkages attached to a sensor of some type, most likely mechanical over hydraulic.


I have just had another look at your 2nd photo and at the end and behind the extension at the larger opening, you will see a plunger in the tractor rear case, this is the actuator for the sensing of the draft control when plowing or using tynes, this works when the tractor wheel spins and sinks into the ground, pressure is brought to bear on the top link (opposite to carrying) and this then pushes the pivot link onto the plunger which through the system causes the implement to be momentarily lifted so the tractor regains its traction and the implement will then be reset to its original ploughing height and the cycle will continue.

there is nothing to say you can't use the top extension, if the pivot section presses against a spring at the rear in the tractor case, you may want to consider that the spring will take a lot of jolts when transporting an implement on rough track or road.


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## pogobill (Jan 31, 2012)

I can't tell if the link that is pinned to the tractor is attached to anything in behind. If the link piece is loose and just hangs there, Remove it and use the existing pin to hook up your top link. If you are going to be doing any serious plowing, I'd look at finding the proper pin.
The set up on that tractor has the cupped section of that link below the "large Hole", will press the button behind it if, for instance your plow digs in deep and causes the top link to tip forward, pushing the Draft control button and causes the plow to rise up if it goes too deep. That is the best guess for that odd link with the grease nipple on it that I can glean from the parts schematic.


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## hd883chopper (Nov 12, 2018)

FredM said:


> I have just had another look at your 2nd photo and at the end and behind the extension at the larger opening, you will see a plunger in the tractor rear case, this is the actuator for the sensing of the draft control when plowing or using tynes, this works when the tractor wheel spins and sinks into the ground, pressure is brought to bear on the top link (opposite to carrying) and this then pushes the pivot link onto the plunger which through the system causes the implement to be momentarily lifted so the tractor regains its traction and the implement will then be reset to its original ploughing height and the cycle will continue...





pogobill said:


> The set up on that tractor has the cupped section of that link below the "large Hole", will press the button behind it if, for instance your plow digs in deep and causes the top link to tip forward, pushing the Draft control button and causes the plow to rise up if it goes too deep. That is the best guess for that odd link with the grease nipple on it that I can glean from the parts schematic.


Thank you and I think your both right! Ok I have a better understanding of that mechanism there. And knowing that, I probably will not be modifying and/or removing that pin. Guess I’ll be hunting down the proper pin. Strange as it seems with one large end and one small. I may have to go see a Case dealer to see if they can find a replacement.


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## Hoodoo Valley (Nov 14, 2006)

The additional photos helped a lot. That mechanism needs to stay in place like the others have stated. It looked like it was just an extra piece at first, but the spring clearly shown now in the latest photos means that it can't be removed. Looks like you need the proper pin. I'd also try to locate a manual for your tractor, as it would have outlined what is needed there.


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## hd883chopper (Nov 12, 2018)

Hoodoo Valley said:


> The additional photos helped a lot. That mechanism needs to stay in place like the others have stated. It looked like it was just an extra piece at first, but the spring clearly shown now in the latest photos means that it can't be removed. Looks like you need the proper pin. I'd also try to locate a manual for your tractor, as it would have outlined what is needed there.


Thank you. Yep I’ll try to see if it’s listed in the old manual I have. It’s not very complete. But I can also go see the local Case Dealer. They’ve been helpful in the past. I had no idea that spring was for. Thx!


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## hd883chopper (Nov 12, 2018)

FredM said:


> you will see a plunger in the tractor rear case, this is the actuator for the sensing of the draft control when plowing or using tynes, this works when the tractor wheel spins and sinks into the ground, pressure is brought to bear on the top link (opposite to carrying) and this then pushes the pivot link onto the plunger which through the system causes the implement to be momentarily lifted so the tractor regains its traction and the implement will then be reset to its original ploughing height and the cycle will continue.


 Hello Fred, thank you for the explanation but I’m curious, if the rear tractor tire sinks causing upward pressure on the implement and top link, wouldn’t it just compress that spring? How does that action momentarily lift the implement?


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## FredM (Nov 18, 2015)

hd883chopper said:


> Hello Fred, thank you for the explanation but I’m curious, if the rear tractor tire sinks causing upward pressure on the implement and top link, wouldn’t it just compress that spring? How does that action momentarily lift the implement?


when you raise the 3 point linkage, the weight of the implement will be exerted on the top link and pull the link against the pivot point (where the zerk is) and compress the spring, the other action is when plowing and the draught is set for depth and as the tractor pulls the plow and the plow hits a hard spot and causes the drive to momentarily lose traction, this causes the tractor rear to dig in and displace dirt and the tractor sinks down, when this happens you have the opposite on the top link and this then causes the implement to push on the top link and this then pushes the extension on the pivot link to press against the plunger on the rear of the tractor and when that happens, the implement will rise until traction is regained, the plunger is connected to the hydraulics and when activated, this will cause the lower links to lift the implement to regain traction.

When working ground with plow, tines or even a box blade, that top pivot works two ways, push and pull, that is why there is the zerk in the pivot point, a parts schematic would most likely show another spring under the the tractor housing so the pivot would be damped both ways.

Once you start plowing and if the draught control is working ok, you will feel/notice the action as you go along.


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## pogobill (Jan 31, 2012)

FredM said:


> I have just had another look at your 2nd photo and at the end and behind the extension at the larger opening, you will see a plunger in the tractor rear case, this is the actuator for the sensing of the draft control when plowing or using tynes, this works when the tractor wheel spins and sinks into the ground, pressure is brought to bear on the top link (opposite to carrying) and this then pushes the pivot link onto the plunger which through the system causes the implement to be momentarily lifted so the tractor regains its traction and the implement will then be reset to its original ploughing height and the cycle will continue.
> 
> there is nothing to say you can't use the top extension, if the pivot section presses against a spring at the rear in the tractor case, you may want to consider that the spring will take a lot of jolts when transporting an implement on rough track or road.


Sorry Fred, I didn't see your post before I posted about the plunger. I guess I should research before I reply, and not during!!


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## hd883chopper (Nov 12, 2018)

FredM said:


> when you raise the 3 point linkage, the weight of the implement will be exerted on the top link and pull the link against the pivot point (where the zerk is) and compress the spring, the other action is when plowing and the draught is set for depth and as the tractor pulls the plow and the plow hits a hard spot and causes the drive to momentarily lose traction, this causes the tractor rear to dig in and displace dirt and the tractor sinks down, when this happens you have the opposite on the top link and this then causes the implement to push on the top link and this then pushes the extension on the pivot link to press against the plunger on the rear of the tractor and when that happens, the implement will rise until traction is regained, the plunger is connected to the hydraulics and when activated, this will cause the lower links to lift the implement to regain traction.
> 
> When working ground with plow, tines or even a box blade, that top pivot works two ways, push and pull, that is why there is the zerk in the pivot point, a parts schematic would most likely show another spring under the the tractor housing so the pivot would be damped both ways.
> 
> Once you start plowing and if the draught control is working ok, you will feel/notice the action as you go along.


Fred, thank you very much for taking the time to write out that explanation. I really appreciate it. 

I had to re read it a couple of times to let it sink in but I think I see what you’re saying and it does make sense. 

Question though... when you say _“the plunger is connected to the hydraulics and when activated, this will cause the lower links to lift the implement to regain traction.”_ Does this mean that the lower links will lift on their own when the implement digs down or does the operator need to do something when this happens?


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## FredM (Nov 18, 2015)

pogobill said:


> Sorry Fred, I didn't see your post before I posted about the plunger. I guess I should research before I reply, and not during!!


2 answers could be better than one Bill, so no worries, alls good.


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## FredM (Nov 18, 2015)

hd883chopper said:


> Question though... when you say _“the plunger is connected to the hydraulics and when activated, this will cause the lower links to lift the implement to regain traction.”_ Does this mean that the lower links will lift on their own when the implement digs down or does the operator need to do something when this happens?


if your hydraulic system is in good working order, the system will work itself once you have started plowing or tyneing and you have set the draught/depth control on the right of your seat to an acceptable depth that the tractor can handle, you have to start plowing or tyneing and as you go along, you will get the feel for the tractor and depth setting on the manual control, then the sensing side of the action should take over.

To understand what I am trying to help you with, picture in your mind a plow hanging off the back of your tractor, off of the ground, the top link is now holding the load and the spring connected to the pivot will be compressed somewhat, now picture the rear of the plow resting on a wood block after lowering the plow so the rear will rest on the block, now the top link is pushing against the sensing pivot and the extension will actuate the plunger in the rear of the tractor housing, so when you are plowing, the pivot will be continually moving backwards and forwards adjusting the depth settings as you travel along.

sometimes the operator will have to manually adjust the depth control because the automatic side only lifts enough to keep the tractor moving, ground conditions decide how things go.


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## Mark68 (Jun 21, 2019)

FredM said:


> if your hydraulic system is in good working order, the system will work itself once you have started plowing or tyneing and you have set the draught/depth control on the right of your seat to an acceptable depth that the tractor can handle, you have to start plowing or tyneing and as you go along, you will get the feel for the tractor and depth setting on the manual control, then the sensing side of the action should take over.
> 
> To understand what I am trying to help you with, picture in your mind a plow hanging off the back of your tractor, off of the ground, the top link is now holding the load and the spring connected to the pivot will be compressed somewhat, now picture the rear of the plow resting on a wood block after lowering the plow so the rear will rest on the block, now the top link is pushing against the sensing pivot and the extension will actuate the plunger in the rear of the tractor housing, so when you are plowing, the pivot will be continually moving backwards and forwards adjusting the depth settings as you travel along.
> 
> sometimes the operator will have to manually adjust the depth control because the automatic side only lifts enough to keep the tractor moving, ground conditions decide how things go.


My 2012 mahindra 4025 has the same type of upper link pin. Cant say that it's the same size as what you need but it might be worth looking at


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## LouNY (Dec 15, 2016)

I'm just seeing your post now. Many of the IH tractors used that stepped pin for the top link.
The small end is actually a cat 1 size and the larger end is cat 2. The pin is available from several suppliers or your friendly IH dealer.
You can use a cat 1 top link pin and a 1 to 2 top link bushing may take two to be long enough.


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## bontai Joe (Sep 16, 2003)

As a designer of machinery for industrial use for over 40 years, when I see a set-up like that with a big hole on one side and a small hole on the other, I automatically think "shoulder bolt". Shoulder bolts are hardened steel bolts with a precision diameter shaft under the head of the bolt of varying specified length to ride in a bearing surface with minimal tolerance, and with the end having a reduced diameter thread which either screws into the small end of the yoke, or is held in place with a locking nut. They are much harder than the typical soft steel pin for minimal wear. A typical shoulder bolt might have a 1" dia. precision shaft with a 3/4" dia thread at the end. The locking nut at the end will clamp tightly against both sides of the small hole in the yoke, allowing the shaft to freely spin thru the rest of the yoke and what is pivoting on it.


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## robertgrisham (Jun 7, 2011)

Hello hd,
Haven't posted for a long while but thought my 2 cents worth might help. 
I have a IH 2400A, 3 cylinder diesel and my 3-point setup is same as your 364. My lower arm links have stepped pins in them. The top link also has the different size holes same as your top link. To solve the top link size problem I use a pin that fits the smaller hole and a long bushing to fit the large hole. My top link (I used a hyd. cylinder) also has the large hole size so the bushing has to be long enough to go through the top link hole and the large hole and held in place with a link pin.


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## hd883chopper (Nov 12, 2018)

FredM said:


> if your hydraulic system is in good working order, the system will work itself once you have started plowing or tyneing and you have set the draught/depth control on the right of your seat to an acceptable depth that the tractor can handle, you have to start plowing or tyneing and as you go along, you will get the feel for the tractor and depth setting on the manual control, then the sensing side of the action should take over.
> 
> To understand what I am trying to help you with, picture in your mind a plow hanging off the back of your tractor, off of the ground, the top link is now holding the load and the spring connected to the pivot will be compressed somewhat, now picture the rear of the plow resting on a wood block after lowering the plow so the rear will rest on the block, now the top link is pushing against the sensing pivot and the extension will actuate the plunger in the rear of the tractor housing, so when you are plowing, the pivot will be continually moving backwards and forwards adjusting the depth settings as you travel along.
> 
> sometimes the operator will have to manually adjust the depth control because the automatic side only lifts enough to keep the tractor moving, ground conditions decide how things go.


Thanks Fred for the info. This was very helpful and I definitely learned something new. Thanks!


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## FredM (Nov 18, 2015)

you are welcome!!.


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## hd883chopper (Nov 12, 2018)

LouNY said:


> I'm just seeing your post now. Many of the IH tractors used that stepped pin for the top link.
> The small end is actually a cat 1 size and the larger end is cat 2. The pin is available from several suppliers or your friendly IH dealer.
> You can use a cat 1 top link pin and a 1 to 2 top link bushing may take two to be long enough.


You sir are exactly correct! So after reading the previous posts and thinking, I was thinking...there's got to be an easy solution for this. Anyway, I drove out to a Case and Mahindra dealer that I've worked with in the past and sure enough, even the new Mahindra's are set up this way. Just as you said Lou. The design is set up to switch between Cat 1 and Cat 2. By switching the pin, you can go back and forth. Bought the Cat 2 version and learned something new. Thanks y’all


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## deerhide (Oct 20, 2016)

My DB is Cat II, the MF135 is Cat.I. I have stepped pins and Cat.II sized pins, long bolts and pins that came off of an ox cart, some too short except for the top link....and I have bushings and thick washers. And then I have some metric equipment. It goes on and on and on......somewhere some 'pin designer' is reading this kind of stuff and laughing.


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## bontai Joe (Sep 16, 2003)

WOW! Okay, I learned something today, which is always a good thing.


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