D Hook Hitch Shackle

[FJ Cruiser]

Where's the best place to get one of these guys?

[flyingwil]

Are you looking for the Receiver Shackle Bracket (http://www.sierraexpeditions.com/index.php/action/item/id/133/prevaction/category/previd/1/prevstart/0/)?

http://www.sierraexpeditions.com/images/products/receiver.jpg

We are out of stock on them, but do have a similar on built by Smitty Built for the same price of $44.99

[FJ Cruiser]

yes. is the Warn unit the best way to go?

[flyingwil]

yes. is the Warn unit the best way to go?

Both are almost exactly the same.

[FJ Cruiser]

okay, I'll order one form you. do you alos carry the hitch pin?

[mountainpete]

Where's the best place to get one of these guys?

Wil is the best place - www.sierraexpeditions.com. And add some quick-fist clamps to your order while you're add it. He has them at a great price and they are ever so handy :elkgrin:

[flyingwil]

okay, I'll order one form you. do you alos carry the hitch pin?

I would recomend a locking one... similar to this one (http://www.sierraexpeditions.com/index.php/action/item/id/249/prevaction/category/previd/5/prevstart/0/):
http://www.sierraexpeditions.com/images/products/thumb_universal.jpg
It is only a few buck more and lockable.

Here is our selection though...
http://www.sierraexpeditions.com/index.php/action/category/id/5/subid/43/

[IggyB]

What's wrong with putting the strap loop straight into the hitch and putting the pin throgh that?

[FJ Cruiser]

What's wrong with putting the strap loop straight into the hitch and putting the pin throgh that?


it's been done, but experts say it should be a last resort - I really don't see why?

[IggyB]

As long as the hitch does not have sharp corners that can cut the rope, it seems as good of an attachment point as any.

[mountainpete]

I think the angles are key. I have used the loop and pin method too and it works fine for straight pulls.

For pulling at an angle, the receiver plug distributes the force of the sideways pull through multiple sides of the recevier box because of it's length. With just the strap, it puts all the force of the pull on one side of the receiver box thus creating a greater chance of failure. I believe that type of pull also increases the load on the pin.

Plus there is the abrasion factor and those sharp corners you mentioned.

Pete

[p1michaud]

What's wrong with putting the strap loop straight into the hitch and putting the pin throgh that?


it's been done, but experts say it should be a last resort - I really don't see why?

The other thing to consider is that your hitch pin is designed and sized to take the load in double shear (i.e. the pin resists the cutting force due to a load right where the hitch and receiver meet). The strap loop into the hitch method works but it does apply a bending moment accross the length of the pin. Does that make sense, I wish I could find a picture to explain this better...

Bottom line, for $50 dollars the Receiver Shackle Bracket will provide a solid anchor point that uses the hitch and pin as they were designed to be used (double shear). If you are in a bind, the strap loop intot he receiver method can be used.
Cheers :beer:,
P

[IggyB]

That makes sense :clapsmile

[FJ Cruiser]

I would recomend a locking one... similar to this one (http://www.sierraexpeditions.com/index.php/action/item/id/249/prevaction/category/previd/5/prevstart/0/):
http://www.sierraexpeditions.com/images/products/thumb_universal.jpg
It is only a few buck more and lockable.

Here is our selection though...
http://www.sierraexpeditions.com/index.php/action/category/id/5/subid/43/

Just placed the order. Thanks for your help.

[MountainBiker]

I'm curious. What are the pros/cons of the D-Shackle vs. a reciever tow hook, like this one below?
http://store.summitracing.com/partdetail.asp?autofilter=1&part=CHT%2DD%2D325&N=700+115&autoview=sku

[DaveInDenver]

The other thing to consider is that your hitch pin is designed and sized to take the load in double shear (i.e. the pin resists the cutting force due to a load right where the hitch and receiver meet). The strap loop into the hitch method works but it does apply a bending moment accross the length of the pin. Does that make sense, I wish I could find a picture to explain this better.
One other thing to keep in mind about these (I use the Smitty, the Warn works fine, too) is the hitch pin. Most people are using a class III hitch pin, which is typically a 5/8" pin made from C1018. This steel is not particularly strong, roughly 60 ksi yield and 5/8" pin has about 0.31 sq-in of area. It's better to use a 5/8" grade 8 bolt, which is 150 ksi. BTW, ksi short for thousands of pounds per square inch, so 120 ksi is 120,000 lbs/sq-in. The rule I remember is to take 50% of ultimate yield in tension and that is your ultimate shear yield. So a 5/8" hitch pin will yield at about 9300 lbs, where as a grade 8 bolt will yield in shear at just over 23,000 lbs.

[teotwaki]

I'm curious. What are the pros/cons of the D-Shackle vs. a reciever tow hook, like this one below?
http://store.summitracing.com/partdetail.asp?autofilter=1&part=CHT%2DD%2D325&N=700+115&autoview=sku

Your strap will never get out of a D shackle that has the pin screwed in tight.

Let's say you bought the hook instead of a D shackle and are using a recovery strap which is semi-elastic (not a static line tow strap). You set up the strap and give a big ol' tug to someone who is stuck, the strap stretches, the stuck vehicle surges forward and for a moment the tension is off of the strap. The end of the strap on your hook jiggles forward and up, just as your vehicle move forward. The strap either flies off completely or worse, impales itself on the hook and is ruined.

A D-shackle is fool proof in comparison.

[teotwaki]

One other thing to keep in mind about these (I use the Smitty, the Warn works fine, too) is the hitch pin. Most people are using a class III hitch pin, which is typically a 5/8" pin made from C1018. This steel is not particularly strong, roughly 60 ksi yield and 5/8" pin is about 0.31 sq in in area. It's better to use a 5/8" grade 8 bolt, which is 150 ksi. BTW, ksi short for thousands of pounds per square inch, so 120 ksi is 120,000 lbs/sq in. The rule I remember is to take 50% of ultimate yield in tension and that is your ultimate shear yield. So a 5/8" hitch pin will yield at about 9300 lbs, where as a grade 8 bolt will yield in shear at just over 23,000 lbs.

It would be nice to get a bolt with the right length of unthreaded shoulder so that it has a nice smooth metal to metal interface with the shackle bracket.

[DaveInDenver]

It would be nice to get a bolt with the right length of unthreaded shoulder so that it has a nice smooth metal to metal interface with the shackle bracket.
Yeah, should have mentioned that. You need to get a pretty long bolt with about 3" of shoulder for it to work. My mistake for forgetting to say that.

[teotwaki]

Yeah, should have mentioned that. You need to get a pretty long bolt with about 3" of shoulder for it to work. My mistake for forgetting to say that.

Figured it was an oversight but you got me to thinking about hunting down the right bolt. I agree that it might take a hacksaw to get the overall length just right. I would like stainless too in order to minimize oxidation.

[asteffes]

Wouldn't you want the pin to act as a fuse in the system to prevent permanent damage to the frame? My Tacoma is rated at 6500 pounds towing capacity, which I figure has something to do with the frame and hitch strength, not just the tranny.

[DaveInDenver]

Figured it was an oversight but you got me to thinking about hunting down the right bolt. I agree that it might take a hacksaw to get the overall length just right. I would like stainless too in order to minimize oxidation.
Most hitch pins are made from 304 stainless, which has about the same strength as C1080. If memory serves, 304 is about 75 ksi yield. I agree corrosion resistance would be nice, but you really need a heat treated pin if you are concerned about its strength, which means a graded bolt of some sort. Hitch pins are almost never heat treated and since they achieve their rated strength of about 5000 lbs without it, no one is going to actually grade a Class III hitch pin.

[DaveInDenver]

Wouldn't you want the pin to act as a fuse in the system to prevent permanent damage to the frame? My Tacoma is rated at 6500 pounds towing capacity, which I figure has something to do with the frame and hitch strength, not just the tranny.
NO!

The last thing you want is a piece of recovery gear breaking. You'd rather have the frame tweak before having a projectile.

People get killed that way!

Edit: If you are concerned with your truck being damaged in a recovery, then you probably should let someone else handle it. I don't want to sound mean, but the guy in the other truck is putting his trust in you that you are not going to endanger him.

[asteffes]

I'm not concerned about damaging my truck. :) My question was really just to bring up the issue, as I've heard it mentioned by others (not here) that they wanted a means of preventing permanent bending or other damage. It does, indeed, sound scary to have anything breaking off and flying about during a recovery.

All that said, has anyone heard of one of these hitch pins breaking during a recovery? Is this a big problem that I'm just not aware of? I understand your concerns. I'm just wondering if this is something that you've whitnessed or heard of actually happening, as I have not.

[DaveInDenver]

I'm not concerned about damaging my truck. :) My question was really just to bring up the issue, as I've heard it mentioned by others (not here) that they wanted a means of preventing permanent bending or other damage. It does, indeed, sound scary to have anything breaking off and flying about during a recovery.

All that said, has anyone heard of one of these hitch pins breaking during a recovery? Is this a big problem that I'm just not aware of? I understand your concerns. I'm just wondering if this is something that you've whitnessed or heard of actually happening, as I have not.
I didn't mean to imply it, just saying it out loud. I am not a professional and hopefully the Tread Lightly! trainers and stuff will correct me. It is my understanding that you NEVER want to knowingly install a part that is not maximized for strength in the recovery chain-of-gear. I don't know what the safe margin for a piece of gear is.

Yup, to be perfectly honest I've never seen a broken hitch pin. It is theoretical in my experience. Still, I personally use a grade 8 bolt. Then again, the working limit on a 3/4" bow shackle is only 4.75 tons anyway...

[p1michaud]

One other thing to keep in mind about these (I use the Smitty, the Warn works fine, too) is the hitch pin. Most people are using a class III hitch pin, which is typically a 5/8" pin made from C1018. This steel is not particularly strong, roughly 60 ksi yield and 5/8" pin has about 0.31 sq-in of area. It's better to use a 5/8" grade 8 bolt, which is 150 ksi. BTW, ksi short for thousands of pounds per square inch, so 120 ksi is 120,000 lbs/sq-in. The rule I remember is to take 50% of ultimate yield in tension and that is your ultimate shear yield. So a 5/8" hitch pin will yield at about 9300 lbs, where as a grade 8 bolt will yield in shear at just over 23,000 lbs.

Excellent point on material selection.
From the numbers above, you make the assumption that the hitch pin is in single shear. In my mind, the hitch pin is in double shear with both sides of the receiver trying to shear the pin. In that case, the yield numbers will be twice those numbers due to doubling the shear area (i.e. 18 600 lbs and 46 000 lbs respectively). Not trying to cause grief, just making sure that readers get the correct information.
Cheers,
P

[DaveInDenver]

Excellent point on material selection.
From the numbers above, you make the assumption that the hitch pin is in single shear. In my mind, the hitch pin is in double shear with both sides of the receiver trying to shear the pin. In that case, the yield numbers will be twice those numbers due to doubling the shear area (i.e. 18 600 lbs and 46 000 lbs respectively). Not trying to cause grief, just making sure that readers get the correct information.
Cheers,
P
That's a good question and I'd think you are right. I have to further qualify by saying I'm just a plain only sparky, so my mechanical is barely passable freshman level. Anyway, my assumption was largely based on the fact that it's a very poor interface fit and loaded off angle quite severely, so the bolt must withstand the force equivalent to single shear because of that. I do think it's actually a double shear problem, though.

Anyway, for clarity, here's what we're talking about.

http://www.roymech.co.uk/images5/bolt_1.gif

[Xtreme XJ]

Thought I'd dredge this thread back up....
What are the thoughts about domestic vs. imported D-rings?
It's hard to find a domestic D-ring any more.... including the 2 mentioned at the begining of this thread....
American Co. yet both imports.

Curt :safari-rig:

[Bayou Boy]

Thought I'd dredge this thread back up....
What are the thoughts about domestic vs. imported D-rings?
It's hard to find a domestic D-ring any more.... including the 2 mentioned at the begining of this thread....
American Co. yet both imports.

Curt :safari-rig:

Try the Crosby shackles as opposed to these Chinese Shackles. THe second you unscrew the bolt you will notice the difference. THe Crosby is like a normal graded bolt while the imported stuff is like a rough generic galvanized olt and nut. An immediate difference. I used to use the Chinese stuff. I bought a couple of Crosby shackles and will never go back.

[teotwaki]

Try the Crosby shackles as opposed to these Chinese Shackles. THe second you unscrew the bolt you will notice the difference. THe Crosby is like a normal graded bolt while the imported stuff is like a rough generic galvanized olt and nut. An immediate difference. I used to use the Chinese stuff. I bought a couple of Crosby shackles and will never go back.

Who has the best price on them?

[Bayou Boy]

Who has the best price on them?

I get them at a local oilfield supply place here. They have them in stock and the tax offsets the shipping. I think Quadratec carries them though.

[teotwaki]

I get them at a local oilfield supply place here. They have them in stock and the tax offsets the shipping. I think Quadratec carries them though.

Thanks! My Google search turned up UK sources but not these guys.

http://www.quadratec.com/products/product_search.php?kw=shackle

[ntsqd]

.....
Most people are using a class III hitch pin, which is typically a 5/8" pin made from C1018. This steel is not particularly strong, roughly 60 ksi yield and 5/8" pin has about 0.31 sq-in of area. It's better to use a 5/8" grade 8 bolt, which is 150 ksi. BTW, ksi short for thousands of pounds per square inch, so 120 ksi is 120,000 lbs/sq-in. The rule I remember is to take 50% of ultimate yield in tension and that is your ultimate shear yield. So a 5/8" hitch pin will yield at about 9300 lbs, where as a grade 8 bolt will yield in shear at just over 23,000 lbs.
A great resource for this type of info is Matweb (http://www.matweb.com). Where you're doing critical (i.e. Life Dependent) calcs you'll want to consult other sources too.

Cold Drawn 1018: (http://www.matweb.com/search/SpecificMaterial.asp?bassnum=M1018A) YTS = 53.7ksi
(YTS = Yield Tensile Strength)

304 Stainless: (http://www.matweb.com/search/SpecificMaterial.asp?bassnum=MQ304A) YTS = 31.2ksi

Estimating Shear at 50% of YTS is low, but that is the safe & conservative side to be on.

FWIW a SHCS is both stronger and more Ductile than a G8 bolt. If the socket head is an issue & you wish to stay with a hex head bolt then I would use a F911 bolt (http://www.f911.com/fore2b.html) as they have similar performance numbers to that of SHCS'.


It would be nice to get a bolt with the right length of unthreaded shoulder so that it has a nice smooth metal to metal interface with the shackle bracket.
It's hard b/c they aren't really sold that way, but if you buy the bolt by it's shoulder length you can then use a washer or two to make sure that the nut does not bind on the end of the threads. SAE bolt shoulder lengths are slightly inconsistant. This need for spacing is exactly what drove the design & mfg of AN washers. Can then cut the threaded section down to 2.5-3 diameters.

Hopefully this info will be of some value to someone.