Winch Shear Pins

[m16ty]

I've had Gerhard's chart since he posted it. After him going through the testing and reading his results, I'm running a brass bolt in my winch. I have several 5/16 brass bolts so I turn them down a bit on the lathe and use them. No broken shear pins or winch yet.

 

[Hooty481]

thats what my intentions were was to use the brass bolts because they are much cheaper than the GI pins that everybody is seling. Also you can buy brass rods on ebay and i think it is a 360 Alloy and it it really cheap...

 

[Jakelc15]

You lost me here.

Are you implying that because brass contains zinc, and Grade 8 bolts are sometimes zinc plated that zinc is some kind of strong wonder metal that breaks winches?

The aluminum alloy that the milspec pins are made from (2024-T361) contains 93.5% aluminum, 4.4% copper, 0.6% manganese and 1.5% magnesium.

Should we infer from that, and the fact that manganese is used in some hard steel alloys that we shouldn't use milspec aluminum shear pins?

It really doesn't matter what your shear pin is made from, as long as it shears with the same number of kpsi as the original 2024-T361 aluminum pins.

-Chuck

The zinc coated bolt comment was just your fun fact for the day.

Where did you find the 2024T361 spec? I read a Mil issued work order for the M44 series shear pin that said 2017. Maybe you found something newer than what I did. From the testing that was done I initially thought they were 2024 by the psi rating.

 

[FormerNewMVGuy]

Does any one know of where i can buy the correct pin for a 5 ton 20,000lb winch?
Havent had much luck on this...

 

[stumps]

The zinc coated bolt comment was just your fun fact for the day.

Where did you find the 2024T361 spec? I read a Mil issued work order for the M44 series shear pin that said 2017. Maybe you found something newer than what I did. From the testing that was done I initially thought they were 2024 by the psi rating.

I didn't know exactly what the alloy was, but based on the shearing information provided earlier, I looked in Machinery's Handbook, and selected the kpsi rating of a common aluminum alloy that seemed to fit the observed results: 2024T361 shears at 42 kpsi. 2017T4 shears at 38 kpsi, which is a tiny bit more conservative.

There are a whole pile of alloys/temperings that give you the same kpsi range: 2014T4, 2014T451, 2017T4, 2017T451, 2018T61, 2024T3, 2024T4, 2024T351, 2024T361, 4032T6... There are several in the 70XX series, but they are getting pretty hard.

I don't really think it is all that critical. I quite suspect that originally the winch used a steel pin, but that broke too many winches, so they softened things up for safety. Aluminum is cheap, doesn't corrode (much), and is light weight, so it is easy on logistics.... 2024T361 is what I would use.

-Chuck

 

[m16ty]

The zinc coated bolt comment was just your fun fact for the day.

Where did you find the 2024T361 spec? I read a Mil issued work order for the M44 series shear pin that said 2017. Maybe you found something newer than what I did. From the testing that was done I initially thought they were 2024 by the psi rating.

I had a mil spec pin tested and it is in fact 2024. The test I had performed didn't tell the temper but T361 seems resonable. Now it could be that the spec changed at some point but the pin I had tested was 2024.

If you read the whole thread you'll see were I had the pin tested.

 

[Recovry4x4]

How much does it end up costing per pin. I've been paying $2.50 for NOS pins delivered. I do buy 20 @ a time.

 

[Hooty481]

Where are you buying them for 2.50?

 

[emr]

Does any one know of where i can buy the correct pin for a 5 ton 20,000lb winch?
Havent had much luck on this...

Gee I have a few for sale,... But geee... I think I remember a hand truck comment in another thread, OH I just sold the last one he he he ........

 

[Recovry4x4]

SGM Pantano but he's not answering his emails right now. Hope all is well. I think I still have about 30 so I'll be OK until he responds.

 

[FormerNewMVGuy]

Gee I have a few for sale,... But geee... I think I remember a hand truck comment in another thread, OH I just sold the last one he he he ........

Prick

 

[lorenplane]

It just seems like alot of work when Saturn Surplus has them for $3.50 each instock....

use 6061 T6 alum. to make your shear pins Saturn Surplus pins are too soft.

 

[lorenplane]

I know Mark, you are practical to the Nth degree, but that takes all the fun out of it, IMHO.
These kind of discussions often lead to new things.

when making your own pins use 6061T6 alum. TSC rods are too soft I get my rods from Aircraft Spruce for .97 per foot

 

[Bob H]

lorenplane,
shear strength of 6061T6 is 30 kpsi
the mil spec 2024T361 is 42 kpsi
therefore the 6061T6 will break sooner.

 

[Maverick1701]

Im going to be playing offroad the weekend of july 10th.

I picked up 3 shear pins from eriks surp. hopefully they will hold...fingers crossed

 

[sedohr]

So I orderd 10 pins from memphis Equipment, they told me yep this is the correct pin for the m35. I recived 10 STEEL pins with flat heads the invoice said -
PIN SHEAR (M37,M715,,GMC,CCKW) . So I called them and told them I need the correct aluminum pin, the guy I spoke to wrote we off as a moron. I asked if they would send call tags to return them as they were wrong and he did. I recived my refund to day, the price I paid was $17.40 for 10 pins and $12.26 for shipping(OUCH) my refund I recived was 3 bucks. Dont get pins from Memphis.

emailed paul at memphis to inquire about this cause frankly, i have NO idea at this time where to get these pins from here's his response: (9/27/11)


These are authentic military surplus pins from the U.S. Government. They are older stock pins made from pot metal when they only made shear pins from pot metal. I have heard all of the talk on Steel Soldiers about how the pins are incorrect if they are made from anything other then Aluminum. I have also heard about how the Aluminum pins break easily before winching a truck out. I have yet to hear anyone say that their winch broke due to our pot metal shear pins. You will just have to be the judge on this issue. Please let me know if you have any more questions.

Thanks Paul

P.S.: Earlier this year we sold 25 M35A2 trucks with winch’s to a foreign military. These trucks have gone thru testing in this country, while I do not know how intense or how much the winches were used-tested. We have had no complaints on anything related to the winch’s or shear pin’s.

randy
ohio

 

[m16ty]

The shear pin SHOULD have been the thing to break first. You may have to take the winch apart to find what broke instead.

Before you test the winch after you fixed the problem, I suggest you check what kind of a shear pin you have in there. Some guys replace their shear pin or shear bolt with something that is much too strong, and then what happened to you happens.

Picture: Shear bolt under my truck

What kind of bolt is that? It's definitely not a stock shear pin.

Due the the extensive testing gringeltaube has done in the past, a actually use a brass bolt in mine. According to G's testing, the brass bolt offers a touch more strength over the stock pin but not enough to tear anything up.

 

[Akicita]

What kind of bolt is that? It's definitely not a stock shear pin.

It's one of the shear bolts that came with the Deuce when I bought it years ago. Sorry, there's no part number I can see - if that's what you're looking for.

 

[rustystud]

The factory bolts are made of aluminum.

 

[73m819]

There is no such thing as a "shear bolt" at least for deuces and 5ts, no matter WHAT was used on you truck when you got it. I would REPLACE your "shear bolt" with the CORRECT shear pin before you break the winch gear case OR bust the pto and transmission.