8N seat hinge bolt. Is there a torque spec?

Tomatoboy

Member
I finally got around to replacing my 1949 8N?s rusty seat pan. The previous owner had just painted over the rust and it quickly became apparent it went
all the way through when the crust flaked off. I noticed when putting it on that the previous seat hinge pin was REALLY honked down. So much that the
new (blue, aftermarket) one from this website didn?t want to fit and I needed to bend the hinge bolt hole tabs back a a few mm to flat again. I?m left
wondering if there is a torque spec on the hinge bolt? I don?t see anything in my IO-4 about the seat hinge at all.
 


You will find that there are torque values for very few fasteners on your N or pretty much anything for that matter. I have a book that gives them for many sizes and hardnesses and materials of bolts and the materials that they go into. As Jim suggested a little googling should give you a number of generic sources such as the one I have.
 
(quoted from post at 16:31:08 01/06/20) That?s what I figured but I just didn?t wanna honk down so hard it bent it again.
Torque specs are determined by grade of bolt. You can google bolt torque specs and there is a chart and it's listed by grade,size and thread. It's not so much an application specific thing it's the fastener that changes what the torque should be.
 
Good evening: I am assuming the bolt goes through fairly soft steel, so when tightening, just watch closely; when you see the metal begin to deform, that is tight enough! Not sure if your tractor has similar seat parts to my 9N, but most of them are not rocket science. Just my opinion....

Dennis M. in W. Tenn.
 

why not just use either Loctite or else a nylock nut and stop tightening before u start to bend stuff?
 
(quoted from post at 21:12:53 01/06/20)
Torque specs are determined by grade of bolt. You can google bolt torque specs and there is a chart and it's listed by grade,size and thread. It's not so much an application specific thing it's the fastener that changes what the torque should be.

should 2 identical bolts get the same torque applied, even if one is threaded into steel and the other into aluminum?

this bolt is a thru bolt, with only a minor amount of resistance to the nut. reading a value off a chart will likely cause those tabs to get squeezed again, i'd think. the application does matter.
 
(quoted from post at 21:41:07 01/06/20)
(quoted from post at 21:12:53 01/06/20)
Torque specs are determined by grade of bolt. You can google bolt torque specs and there is a chart and it's listed by grade,size and thread. It's not so much an application specific thing it's the fastener that changes what the torque should be.

should 2 identical bolts get the same torque applied, even if one is threaded into steel and the other into aluminum?

this bolt is a thru bolt, with only a minor amount of resistance to the nut. reading a value off a chart will likely cause those tabs to get squeezed again, i'd think. the application does matter.


HFJ as I stated the book that I have as well as many others I am sure give the different values for different materials, as well as dry and lubed As I said not hard to find on line.
 
(quoted from post at 00:48:18 01/07/20)
(quoted from post at 21:41:07 01/06/20)
(quoted from post at 21:12:53 01/06/20)
Torque specs are determined by grade of bolt. You can google bolt torque specs and there is a chart and it's listed by grade,size and thread. It's not so much an application specific thing it's the fastener that changes what the torque should be.

should 2 identical bolts get the same torque applied, even if one is threaded into steel and the other into aluminum?

this bolt is a thru bolt, with only a minor amount of resistance to the nut. reading a value off a chart will likely cause those tabs to get squeezed again, i'd think. the application does matter.

HFJ as I stated the book that I have as well as many others I am sure give the different values for different materials, as well as dry and lubed As I said not hard to find on line.

i understand. my point was that u can't just look up specs for the bolt itself. in this case, the bolt isn't screwed into anything, but rather runs thru a pair of holes. without knowing the strength of what those 2 holes are in, which is a function of material, thickness, and probably other features too, i don't see where this is something to simply be looked up.

i just went out to look at mine, and not surprisingly, it's a locknut. tighten it till it's snug, and you're done. no research needed :)
 
(quoted from post at 00:56:35 01/07/20)
(quoted from post at 00:48:18 01/07/20)
(quoted from post at 21:41:07 01/06/20)
(quoted from post at 21:12:53 01/06/20)
Torque specs are determined by grade of bolt. You can google bolt torque specs and there is a chart and it's listed by grade,size and thread. It's not so much an application specific thing it's the fastener that changes what the torque should be.

should 2 identical bolts get the same torque applied, even if one is threaded into steel and the other into aluminum?

this bolt is a thru bolt, with only a minor amount of resistance to the nut. reading a value off a chart will likely cause those tabs to get squeezed again, i'd think. the application does matter.

HFJ as I stated the book that I have as well as many others I am sure give the different values for different materials, as well as dry and lubed As I said not hard to find on line.

i understand. my point was that u can't just look up specs for the bolt itself. in this case, the bolt isn't screwed into anything, but rather runs thru a pair of holes. without knowing the strength of what those 2 holes are in, which is a function of material, thickness, and probably other features too, i don't see where this is something to simply be looked up.

i just went out to look at mine, and not surprisingly, it's a locknut. tighten it till it's snug, and you're done. no research needed :)

HFJ many people simply do not understand why, how, and where torque is used with fasteners. It's a complex incomprehinsible mystery involving strength of materials, math, and physics.

As a result the idea that torque is essentially meaningless in some fastener applications is equally incomprehinsible. So we wind up with a long thread on how much torque is needed on a seat pan pivot bolt. Proof positive common sense is just about dead :evil:

TOH
 
Yeah, the fact that it was a locknut wasn?t immediately apparent due to the excess of paint on it. I ended up just doing exactly that, tightening it until it
was just snug enough it didn?t interfere with operation of the seat pan flipping up or down.
 
(quoted from post at 05:54:36 01/07/20) Sorry I helped kill common sense. Seemed like a reasonable enough question.
on't worry, it didn't look like everyone intended to be a smart alec. On something like that I tend to do it by feel. Move it till it looks and feels like it was designed to function. Those of us who were born with a tool in hand probably do not have all of our fingers or the chemicals have eroded our brain. At the end of the day you'll be the better.
 
(quoted from post at 08:53:31 01/07/20)

Well, TOH has spoken. I am surprised at such a condemnation from him. Sad.[/quots]

Sorry if I stepped on anyone's toes and I wasn't condemning anyone especially you. But the increasingly prevalent notion that a calibrated torque is required for assembling every damn fastener on a machine is starting to rub me raw. Let's just say I'm getting old and crotchity and I was venting before I had my morning coffee and calmed down. Do please accept my apology for any unintended intemperance.

But I stand by my basic point. If you are going to take on the task of wrenching on machines, especially old machines, you have to learn where a torque specification is and isn't an appropriate concern.

TOH
 
(quoted from post at 06:57:52 01/07/20)
(quoted from post at 08:53:31 01/07/20)

Well, TOH has spoken. I am surprised at such a condemnation from him. Sad.[/quots]

Sorry if I stepped on anyone's toes and I wasn't condemning anyone especially you. But the increasingly prevalent notion that a calibrated torque is required for assembling every damn fastener on a machine is starting to rub me raw. Let's just say I'm getting old and crotchity and I was venting before I had my morning coffee and calmed down. Do please accept my apology for any unintended intemperance.

But I stand by my basic point. If you are going to take on the task of wrenching on machines, especially old machines, you have to learn where a torque specification is and isn't an appropriate concern.

TOH

Apology accepted. You have renewed my faith in man kind, LOL. I have to agree though about the concept of tightening a hinge point however. If I don't have the correct locking nut I will just jam two nuts together. It is a pretty simple concept.
 
One might consider that not everyone using this site has the same level of mechanical knowledge. What is ?pretty simple? or ?common sense? to one
might not be for others. People ask questions to learn/acquire knowledge.

If anybody ever searches for this thread looking for answers about the 8N flip over seat?s (C5NN400AE) hinge pin (352664S), the knowledge I acquired
was...there is no published torque value, and it doesn?t really matter. Also, the nut is a lock nut, there is a washer between it and the hinge, and the
hinge bolt is squared off on the far end in carriage fashion, fitting into a square hole on the hinge so it doesn?t rotate while you tighten in. Over
tightening it can lead to deformation of the hinge holes, making for a tight fit.
 
The orignal N series shop manuals never had a tourk specified for any place on the tractor as Ford did not figure any farmer even knew what a tourk was or even expected any body working on them even knew what a tourk wrench was.
 
Upon further research, I?m not surprised the N-series did not have torque values specified in the original materials, as the torque wrench was a brand spanking new invention when the first N-series tractors were being built, and were almost unheard of when it was being designed. Turns out the first one wasn?t conceived until 1918, the first patents similar to today?s devices were filed in the 30s, and they didn?t really spread until after Chrysler introduced a beam type one in 1938 and then licensed it for sale. I guess if I had known when the wrench was invented, I could have spared myself from having to ask if there might be a published value.

To illustrate how much has changed, nowadays you get a torque value even for things you?d never actually use a torque wrench for...case in point, both of our late model Ford vehicles have a specified torque range for the transmission drain and leveling holes (many modern Ford transmissions like the 6F35 now lack dipsticks and must be leveled off using the hole)...not so you can get it snug enough, but so you know how hard you can honk down before cracking the relatively fragile aluminum transmission case...not very hard at all.
 
(quoted from post at 16:31:08 01/06/20) That?s what I figured but I just didn?t wanna honk down so hard it bent it again.

Just apply a little common sense. It's not a head bolt.
 
(quoted from post at 13:41:38 01/07/20) Upon further research, I?m not surprised the N-series did not have torque values specified in the original materials, as the torque wrench was a brand spanking new invention when the first N-series tractors were being built, and were almost unheard of when it was being designed. Turns out the first one wasn?t conceived until 1918, the first patents similar to today?s devices were filed in the 30s, and they didn?t really spread until after Chrysler introduced a beam type one in 1938 and then licensed it for sale. I guess if I had known when the wrench was invented, I could have spared myself from having to ask if there might be a published value.

To illustrate how much has changed, nowadays you get a torque value even for things you?d never actually use a torque wrench for...case in point, both of our late model Ford vehicles have a specified torque range for the transmission drain and leveling holes (many modern Ford transmissions like the 6F35 now lack dipsticks and must be leveled off using the hole)...not so you can get it snug enough, but so you know how hard you can honk down before cracking the relatively fragile aluminum transmission case...not very hard at all.

It's more than that. Modern assembly line robots (at least for now) are non-sentient machines that need a precise torque value for every fastener they install. Humans on the assembly line are typically using high speed pneumatic or electric tools so they need a torque value for setting their tools. As a result all of those values are engineered and published in the manual along with a lot of other detailed design data.

Humans performing routine service on the vehicle are typically using ordinary hand tools and can think and reason their way through most processes. In general I don't need a torque value to judge how hard I can pull on a common ordinary filler plug in an aluminum housing. And I am not going to take the time to go look up an OEM value in the manual or fetch the proper size torque wrench for something that mundane. I will do it with an ordinary wrench based on 50 odd years of experience. I think you will find that is pretty much SOP in most professional shops.

TOH
 
That is an *excellent* point about why everything has a recorded torque value. Obviously, a
robot or factory worker with hefty power tools needs one on the line. Also an excellent point
about professional shops generally not worrying about such matters, as they know what
does and does not need precise torque. I am not a mechanic or engineer by trade. I did not
grow up on a farm or working on things. Therefore, I have no idea what does and does not
need a torque value. I?m used to vehicles that DO have values for everything. I appreciate
the help everybody has given in calibrating my ?does this need a torque value? threshold. I
was just trying to avoid bending the tabs again.
 
(quoted from post at 11:23:42 01/07/20) That is an *excellent* point about why everything has a recorded torque value. Obviously, a
robot or factory worker with hefty power tools needs one on the line. Also an excellent point
about professional shops generally not worrying about such matters, as they know what
does and does not need precise torque. I am not a mechanic or engineer by trade. I did not
grow up on a farm or working on things. Therefore, I have no idea what does and does not
need a torque value. I?m used to vehicles that DO have values for everything. I appreciate
the help everybody has given in calibrating my ?does this need a torque value? threshold. I
was just trying to avoid bending the tabs again.

I remember one time years ago where I had new tires put on my van. Some time later I went out to my driveway and one of the tires was flat, so I proceeded to change it. There was no way I could loosen those lug nuts with a regular lug wrench. Even my air impact driver would not loosen them. I had to use about a three foot cheater bar to get them loose. I wound up loosening all of the lug nuts and torquing them all down.

About a year or so ago, I had two front tires replaced at a different shop. I was sitting by a window in their office and could see them working on my car. I was totally shocked when the guy put the tires on, of course, with an air impact driver, but then he went back on both tires and used a manual torque wrench to tighten them up. That's the only shop I have ever seen do that.

I wonder how many people around here have had a flat out on the road and could not loosen their lug nuts with a regular lug wrench?
 
(quoted from post at 14:54:18 01/07/20)
(quoted from post at 11:23:42 01/07/20) That is an *excellent* point about why everything has a recorded torque value. Obviously, a
robot or factory worker with hefty power tools needs one on the line. Also an excellent point
about professional shops generally not worrying about such matters, as they know what
does and does not need precise torque. I am not a mechanic or engineer by trade. I did not
grow up on a farm or working on things. Therefore, I have no idea what does and does not
need a torque value. I?m used to vehicles that DO have values for everything. I appreciate
the help everybody has given in calibrating my ?does this need a torque value? threshold. I
was just trying to avoid bending the tabs again.

I remember one time years ago where I had new tires put on my van. Some time later I went out to my driveway and one of the tires was flat, so I proceeded to change it. There was no way I could loosen those lug nuts with a regular lug wrench. Even my air impact driver would not loosen them. I had to use about a three foot cheater bar to get them loose. I wound up loosening all of the lug nuts and torquing them all down.

About a year or so ago, I had two front tires replaced at a different shop. I was sitting by a window in their office and could see them working on my car. I was totally shocked when the guy put the tires on, of course, with an air impact driver, but then he went back on both tires and used a manual torque wrench to tighten them up. That's the only shop I have ever seen do that.

I wonder how many people around here have had a flat out on the road and could not loosen their lug nuts with a regular lug wrench?

In today's world of disc brakes and easily deformed alloy wheels torquing lug nuts has become SOP. Shops typically use one of two procedures:

1) An impact wrench fitted with a torque stick - used by my local high volume tire service center
2) A secondary operation with a manual torque wrench. - used by the local garage that does most of my tire service.

And lest this set off another debate I have heard all of the arguments for and against the use of torque sticks in this application. They are still a common practice in many tire shops.

TOH.
 
I had one immovable lug nut experience many years ago on a 2002 Ford Taurus. I bought it as a former fleet car that the fleet company always
serviced at a particular major service chain. The rear driver tire had a flat, but I couldn?t get any of the lugs to budge with my wrench. Thankfully, it
happened in the driveway, and I was able to locate a fat metal pipe to slot over my lug wrench and break them free. Definitely seen a few people
standing on lug wrenches trying to break one free, too.

Now that you?ve mentioned it, I?ve actually seen a few manual torque wrenches used on wheels over the years while getting service myself. One time
was even at a Ford dealer, although I suspect in that instance it was because they had just competed a major repair and already had the torque wrench
out. Lol. Never seen one just for a quick rotate.
 
Yeah, I?ve typically seen them using the impact with a torque stick approach. Probably 98+ percent of the time. Once in a blue moon I see the torque
wrench come out. I don?t care which one they use as long as they tighten them up right.
 
Although as noted by TOH they are using torque sticks on their impacts (hopefully) to avoid damaging the alloys, etc...
 
Getting back to your original post, it you got it too tight , the seat would not hinge up, too loose, the bolt would be loose. With the self locking nut it will stay where you put it without being too tight. Mine are both so rusty that I doubt that I could get them off, maybe a hot torch!
 
And those tourk stiks do not work, they can tighten to way more than they are supposed to.. Have had to hav shop out toget wheel off they had just worked on and bolt striped. Same shop new tire with ledd than 10 mile blew out for my wife, wrecker happened to be going by and stoped, he could not get nuts of to put on spare, he ended up hauling it back to shop that put tire on. Years ago cousin calld me for help after breaking several lugs of on side of road.
 
I have had many a lug bolt stretched or nuts thread striped with those torque sticke, For a time on job I was having to have new brakes installed every week or lucky two. And tires would only last a month or less. So I have had probably a hundred lug bolts-nuts dammaged with those torque stiks.
 
(quoted from post at 07:23:26 01/07/20)
(quoted from post at 06:57:52 01/07/20)
(quoted from post at 08:53:31 01/07/20)

Well, TOH has spoken. I am surprised at such a condemnation from him. Sad.[/quots]

Sorry if I stepped on anyone's toes and I wasn't condemning anyone especially you. But the increasingly prevalent notion that a calibrated torque is required for assembling every damn fastener on a machine is starting to rub me raw. Let's just say I'm getting old and crotchity and I was venting before I had my morning coffee and calmed down. Do please accept my apology for any unintended intemperance.

But I stand by my basic point. If you are going to take on the task of wrenching on machines, especially old machines, you have to learn where a torque specification is and isn't an appropriate concern.

TOH

Apology accepted. You have renewed my faith in man kind, LOL. I have to agree though about the concept of tightening a hinge point however. If I don't have the correct locking nut I will just jam two nuts together. It is a pretty simple concept.
ooks like you missed my post also.
 
(quoted from post at 11:08:15 01/08/20) I have had many a lug bolt stretched or nuts thread striped with those torque sticke, For a time on job I was having to have new brakes installed every week or lucky two. And tires would only last a month or less. So I have had probably a hundred lug bolts-nuts dammaged with those torque stiks.

Sigh....

[u:3d08d34318]A torque stick is used with an impact wrench[/u:3d08d34318] and operates on much the same principle as a beam type torque wrench. It has a fixed torsional resistance (flexible spring steel shaft) that corresponds to the desired fastener torque. When the fastener hits the target torque the stick begins to flex absorbing the force of the impact wrench hammer blows which prevents the impact wrench from over tightening the fastener. That is simple physics. It works just fine if properly used and will give you accuracy roughly equivalent to a consumer grade torque wrench (i.e. +/- 4%).

What a torque stick cannot do is compensate for an over size impact wrench. For most car tire type sticks the [b:3d08d34318][u:3d08d34318]upper limit[/u:3d08d34318][/b:3d08d34318] on the impact wrench is around 250 lb-ft. If you strap a 800 lb-ft wrench on one of those sticks the individual hammer blows will be so strong they exceed the sticks ability of absorb the force and you wind up over tightening the fastener. It's called operator error. Over tightened to the point you stretched studs would be massive operator error. And once Bubba twists the snot out of that torque stick it is toast and will never again work properly.

TOH
 
(quoted from post at 09:42:29 01/08/20)
(quoted from post at 11:08:15 01/08/20) I have had many a lug bolt stretched or nuts thread striped with those torque sticke, For a time on job I was having to have new brakes installed every week or lucky two. And tires would only last a month or less. So I have had probably a hundred lug bolts-nuts dammaged with those torque stiks.

Sigh....

[u:87681d8798]A torque stick is used with an impact wrench[/u:87681d8798] and operates on much the same principle as a beam type torque wrench. It has a fixed torsional resistance (flexible spring steel shaft) that corresponds to the desired fastener torque. When the fastener hits the target torque the stick begins to flex absorbing the force of the impact wrench hammer blows which prevents the impact wrench from over tightening the fastener. That is simple physics. It works just fine if properly used and will give you accuracy roughly equivalent to a consumer grade torque wrench (i.e. +/- 4%).

What a torque stick cannot do is compensate for an over size impact wrench. For most car tire type sticks the [b:87681d8798][u:87681d8798]upper limit[/u:87681d8798][/b:87681d8798] on the impact wrench is around 250 lb-ft. If you strap a 800 lb-ft wrench on one of those sticks the individual hammer blows will be so strong they exceed the sticks ability of absorb the force and you wind up over tightening the fastener. It's called operator error. Over tightened to the point you stretched studs would be massive operator error. And once Bubba twists the snot out of that torque stick it is toast and will never again work properly.

TOH

Thanks for that info. :wink:
 
Don't mean to poke the "Bear" but there is a good reference on the YT web site for torquing bolts. I printed it out and stapled it to the wall in the shop. With that said I have only used a torque wrench on the head bolts! The rest I kind of go by feel!
 
Thanks! I hadn?t actually seen it was linked right here, although I?ve seen a similar chart
before. Not sure if it would have helped with the original issue as the hinge pin (at least
mine) has no grade markings and I couldn?t find the material data on it. In the end,
everybody is right though, it just needs to be tight enough to keep the pin from wobbling,
and loose enough to allow the seat to move and to not deform the tabs.

The new seat is really a relief, the old one was uncomfortable even through my seat pad.
 

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