When to replace the hitch pin?

[swimmer_spe]

The pin for holding the hitch into the receiver is the only real thing holding our trailers to our trucks. Mine is new, but it got me thinking, how often should it be replaced?

[Grit_dog]

^Yup, you’re correct. Although also correct. I didn’t pickup on your reference to iron, as in cast iron, of which NO hitch pins are made of. And I understand this concept better than most.
Why would you even say that? Be like using a wooden dowel or titanium as odd ball “examples”.
Although the silly original question may have prompted your almost as silly comparison?

3 pages in, it’s a hitch pin, it’ll be fine. End of story. OP can now sleep well with visions of hitch pins NOT breaking dancing in his head!

[valhalla360]

Grit dog wrote:
^Nope, but those may be good numbers for aluminum or brass or something. Hence why there’s no such thing as an aluminum hitch pin. You could rip 15000lbs in half just puttin the wood to it pulling your camper out of the driveway. (Not literally but it likely would not make it to the first campground.)
Any good hitch pin and maybe even the cheap $3 ones is going to have a shear strength FAR greater. Take normal 36ksi yield mild steel (that’s tensile strength). Ultimate tensile is more like 50ksi. Round numbers and approx.
Hitch pins are or should be 50-60-80ksi steel and shear is about 80% of tensile.

The factor of safety is 5-10 or idk maybe more.

Now bending is a different story. And why those silly reducer inserts for the trucks with 2.5-3” hitches are a horrible solution to being cheap with your hitch stingers.
The insert creates a short bending moment in the hitch pin and can and will easily pretzel a hitch pin. (And Waller out the holes in your hitch receiver, generally prior to bending the pin.)
I’ve cut off numerous bent pins due to those stupid little accessories.

Show me a strain guage showing 15k lbs on a 10,000 lb bumper pull. A truck with 7000 on the rear axle and sticky tires with a 50% coefficient of friction with only be able to apply 3500lb of shear force to the pin. Lock up all 4 wheels on a 10,000 lb truck and you are around 5000lb applied to the pin. But in normal use even those numbers are unrealistically high.

Also, try reading....I specifically said iron not steel as a worst case scenario and that steel can easily double the strength.

This is a shear failure so work in shear strength not tensile strength.

If you start mismatching parts of course you can have problems.

The point is even with the worst case scenario the pin is still several times stronger than needed.

[Grit_dog]

A cheap one won’t shear either. Maybe unless your trailer rear ended by a loaded semi truck while you simultaneously an actual brick wall in front of you.

[Cummins12V98]

Quality US Made pin should never sheer.

[Grit_dog]

^Nope, but those may be good numbers for aluminum or brass or something. Hence why there’s no such thing as an aluminum hitch pin. You could rip 15000lbs in half just puttin the wood to it pulling your camper out of the driveway. (Not literally but it likely would not make it to the first campground.)
Any good hitch pin and maybe even the cheap $3 ones is going to have a shear strength FAR greater. Take normal 36ksi yield mild steel (that’s tensile strength). Ultimate tensile is more like 50ksi. Round numbers and approx.
Hitch pins are or should be 50-60-80ksi steel and shear is about 80% of tensile.

The factor of safety is 5-10 or idk maybe more.

Now bending is a different story. And why those silly reducer inserts for the trucks with 2.5-3” hitches are a horrible solution to being cheap with your hitch stingers.
The insert creates a short bending moment in the hitch pin and can and will easily pretzel a hitch pin. (And Waller out the holes in your hitch receiver, generally prior to bending the pin.)
I’ve cut off numerous bent pins due to those stupid little accessories.

[valhalla360]

mosseater wrote:
Any idea what the shear forces required to chop it in two? There are anomalies in this world but betting the farm very few ever are sheared. The receiver welds would probably fail before that pin would shear. I'd sooner keep the one I have road tested than risk a new one these days.

5/8inch pin has a cross sectional area of around 0.30in^2.

It will depend on the specific steel but say we made one of iron (not steel for a worst case scenario). Iron has a shear strength of around 26,000PSI.

So each end of the pin would have a strength of around 7,800 but since both ends would have to shear to get a failure, 15,600lb.

A descent quality steel (nothing exotic) can be twice that shear strength.

Keep in mind, when you tow, you aren't lifting the weight of the trailer. The force needed to pull the trailer is a small fraction of the trailer weight. Even in a panic stop, the trailer would push the truck into a skid long before the force reached the weight of the trailer.

So long as there is no sign of damage or deformation, it should be fine.

[Grit_dog]

mosseater wrote:
Any idea what the shear forces required to chop it in two? There are anomalies in this world but betting the farm very few ever are sheared. The receiver welds would probably fail before that pin would shear. I'd sooner keep the one I have road tested than risk a new one these days.

Bout 28000lbs. Times 2 of course since there’s 2 shear planes.
This is not has not been and won’t ever be an issue. Nor is wearing one out.

[Lawman5383]

I've been in RV transport for a while now and have never seen or heard of a pin failing. This is not to say they couldn't fail. Prior to this I was a police officer for 29 years and never heard of an accident caused by a pin failure.

[mosseater]

Any idea what the shear forces required to chop it in two? There are anomalies in this world but betting the farm very few ever are sheared. The receiver welds would probably fail before that pin would shear. I'd sooner keep the one I have road tested than risk a new one these days.

[JRscooby]

swimmer_spe wrote:
OP here.

I tend to replace by loosing them. I have yet to have one look rusted or have any marks on it. I also don't like the idea of replacing it only when the safety chains are used.

Something I have never thought of before; If safety chains are used, get a unknown shock load, should they be replaced?

[swimmer_spe]

OP here.

I tend to replace by loosing them. I have yet to have one look rusted or have any marks on it. I also don't like the idea of replacing it only when the safety chains are used.

[NMDriver2]

If I exposed my pin or any part of my vehicle or attachment hardware to a salt environment I would look for rust each time I used it and replace if it looked weakened.

I've got one pin that I have used 23 years with out any wear or tear. Mostly used to pull the boat and light weight trailers (less than 3000lbs) behind my Astro van. I guess if I lived where rust was an issue I might worry about it or the hitch bolts, welds and other attachment hardware. My truck pulls the 5er and not much else. I do have a spare hitch pin for it somewhere but when I was pulling doubles I used the pin from the van in the 5er hitch to pull the boat. It has been dipped into salt water a time or two but then washed off as soon as possible with fresh water along with the rest of any metal I had near the sea.

[Grit_dog]

swimmer_spe wrote:
The pin for holding the hitch into the receiver is the only real thing holding our trailers to our trucks. Mine is new, but it got me thinking, how often should it be replaced?

I’ll wager a large sum that if you’re ever able to put any significant wear and tear on your hitch pin, by the time that happens, 95% of the current rvnet members will be pushing daisies and I will, at a minimum, be long since retired and on here babbling about hitch pins and other non issues, or also in the ground looking up.

[Grit_dog]

nickthehunter wrote:
When was the last time you have seen someone break a pin?

Break? Never.
Bend? Only when used with a reduced sleeve.
Noticeable loss of cross sectional area due to wear? VERY rarely and likely a pin in daily use for decades.

[Grit_dog]

opnspaces wrote:
If the pin is smooth and undamaged I would leave it alone. I would replace it if it's showing signs of damage like maybe the receiver tube gouging into the surface of the pin.

A few weeks ago I noticed that a replacement pin for a 2 inch receiver is a whole $3 on Amazon. At that price I ordered a few extras since I have multiple hitches at home. I also keep an extra in the center console of the Suburban as a just in case.
Amazon

$3 Scamazon hitch pins are maybe not the best purchase…I’ll leave it at that.