Shear pin for winch , i wonder !!!

[dragonwagon]

I did some reasherching here , see the aluminum pin is normal , i sheered mine today . The pull i was doing was not very hard . Im new on the board so i should state i have been in towing for 34 years so im pretty familure with winches .

1st iv never seen an aluminum sheer pin on any civi winch .

2nd , aluminum can be very strong depending on the alloy so i see where this is a viable sheer pin .

Reading old post i see other guys have found there pins to sheer much easier then they thought they should so my question is this .

Are there " correct " and cheap pins floating around ? Those that are made of the correct material and those that are knock offs persey ?

I should think that winch could easly drag that deuce at 13,530 lbs . I was no where near that when the pin sheered . I know the winch has a 10,000 lb raiting , having been around winches many years id call it underratted . Small electric winch with 3/8 line has that capacity .

Whats the general oppinion on the board ?

 

[ccequipment]

The correct pins are aluminum, and yes they are out of a stronger alloy than normal. I sell ones made out of the correct same material as the original ones, not you normal grade, those will break even easier. Strenght will depend on what type of alluminum you have, but they will still break. Always use a snatch block when draging yourself or anything else out unless its on hard ground with little resitance. Think of it as a fuse or saftey for your winch and it will be cheaper thatn replacing parts. Beware of aftermarket shear pins unless they are made out of the same grade. I sell them in my ebay store if you need some.

 

[Lex_Ordo]

Saturn Surplus has them too, and they are USGI, with the military part number.

 

[cessnatwin]

Same with Memphis Equipment

 

[dragonwagon]

I was on hard surface respooling with a light drag on the brake to spool the cable tight .

Id be surprised if there was more then 3 or 4 K at its peak put against the line . Thats why i became suspect of the pin being some non orginal part stuck in there of an inferior material grade .

 

[73m819]

There is some other things to consider in shear pin use.
1----the fit between the driven and the drive part, if there is slop at all ( not a VERY close fit) it will shear under a lot lower load then the specs call for, the MORE slop, the less load that can be handled. these parts should go together with a slight finger press fit.

2----the fit of the shear pin in the holes( both driven and drive parts) if there is any slop at all the pins will NOT carry the spec load. the pins should go finger SNUG, not just slide in .
Need to check that the holes were not reamed out for a larger pin or bolt
The holes need to be CLEAN, no rust, dirt, ect for the correct snug fit

3----the outside edges of the inside part should not be wallowed out, nor the inside edges of the outside part, if thay are, the pin wont carry the spec load

4----A steady pull, being eased into, will increse the life of the shear pin.

Everytime a shear pin takes a dump, a little more slop is gained at #1 and #3 points

 

[dragonwagon]

Gave it an inspection prior to use , well quick look . But with out actually putting the pin in and out its hard to say regarding fit . Visually it looks excellent .

Another thought i had today , How much resistence may be in that winch with out load . Need to check the winch out better i guess . It may be turning hard for unknown reason creating a load on the pin with nothing on the cable though it does appear to work properly . Ill get the correct pins at a meet next week end then ill have a better idea .

 

[doghead]

You may have increased drag, when under a load, if there is anything wrong with your main drum bearings. So, even if it rotates well with no load, unless you have been inside your winch or rebuilt it, you never really know what's going on in there, under a full load.

 

[M543A2]

I order 6061-T6 aluminum round bar stock from McMaster-Carr and make our pins out of it. It has worked very well in our trucks for many years. We have definitely tested it out with farm equipment recovery operations. They do not have the exact diameter so I buy it a little larger and machine it to the correct diameter. I cut it to the length that allows me to cross-drill each end and put cotter pins in it to retain it in the drive line.
Sometimes a seemingly easy failure like you had is caused by a pin that was partially sheared in a previous operation, then failed more easily later from the damage.

Regards Marti

 

[RAYZER]

I did some reasherching here , see the aluminum pin is normal , i sheered mine today . The pull i was doing was not very hard . Im new on the board so i should state i have been in towing for 34 years so im pretty familure with winches .

1st iv never seen an aluminum sheer pin on any civi winch .

2nd , aluminum can be very strong depending on the alloy so i see where this is a viable sheer pin .

Reading old post i see other guys have found there pins to sheer much easier then they thought they should so my question is this .

Are there " correct " and cheap pins floating around ? Those that are made of the correct material and those that are knock offs persey ?

I should think that winch could easly drag that deuce at 13,530 lbs . I was no where near that when the pin sheered . I know the winch has a 10,000 lb raiting , having been around winches many years id call it underratted . Small electric winch with 3/8 line has that capacity .

Whats the general oppinion on the board ?

Doesn't the winch have a 20k lb rating, (10 ton)?

 

[LanceRobson]

Doesn't the winch have a 20k lb rating, (10 ton)?

Nope. It is 10,000 poundsand that is only on the first layer of cable on a bare drum. Never put a load on the cable with less than 4 full wraps on the drum. The more layers on the winch the less capacity the winch has since it's pulling in more cable per revolution and the winch is doing correspondingly more work per revolution.

Note that Uncle generally sizes thing like shear pins so that they fail long before the winch is in danger. That mentality is also why most vehicles seem underpowered. Uncle doesn't want you twisting off drive line parts every time you get shot at or get excited.

On the lower front of the input side gear case is the cover to a friction band brake that is mounted on the end of the input shaft. It's purpose is to hold the rated load when the clutch is in and the load is downhill from the truck. When adjusted properly and kept clean they will still drag a little as you wind in but it is negligible. If you have just pulled in all 200 feet of cable and the cover is a little warm, things are likely OK. If the cover ever gets hot then you need to check the brake for corrosion and adjust it. When improperly adjusted or corroded they can have your winch loaded to well over 10,000 pounds with no load on the cable. The brake cover is verticle and I've never (in 36 years) seen one that didn't have some degree of corrosion in it.

The -10 TM has all you need to know about adjusting and testing the brake.

The post referring to using a snatch block has much merit. Even if the load is not near the rated (bare drum) capacity the snatch block will let you get more cable off the drum and lower the load on the winch. My motto for winching and lifting operations is "No drama!" so I like a bare or nearly bare drum if we're in any doubt as to the amount of the load.

Lastly, what was the fleet angle (the angle formed by the long axis of the winch drum axle and the cable's path to the load)? It should not be more than 12-15 degrees. Any more and you put side thrust loads on the winch that can damage the winch very quickly (and break shear pins) and it almost guarantees that the cable will be damaged. A snatch block will let you make up to a 180 degree change in the direction of pull. You can winch a load forward that is next to or even in your truck.

If you lost a shear pin that you don't think you should have that raises a red
flag. There was no mention how many layers of cable were on the drum but if it was more than one or maybe two that could be the issue. I'd start looking at the brake, though.

As a general bit of advise, I strongly advise any operator to not use the winch unless they have drained, flushed and filled the gear cases, adjusted both friction brakes and inspected all 200 feet of the cable and cleaned and lubed the cable. Most industrial supply houses and many truck parts shops and farm supply stores sell open gear and cable lube. You'll need 2-3 cans for most winches.

Lance

 

[mudguppy]

There is some other things to consider in shear pin use.
1----the fit between the driven and the drive part, if there is slop at all ( not a VERY close fit) it will shear under a lot lower load then the specs call for, the MORE slop, the less load that can be handled. these parts should go together with a slight finger press fit.

2----the fit of the shear pin in the holes( both driven and drive parts) if there is any slop at all the pins will NOT carry the spec load. the pins should go finger SNUG, not just slide in .
Need to check that the holes were not reamed out for a larger pin or bolt
The holes need to be CLEAN, no rust, dirt, ect for the correct snug fit

3----the outside edges of the inside part should not be wallowed out, nor the inside edges of the outside part, if thay are, the pin wont carry the spec load

4----A steady pull, being eased into, will increse the life of the shear pin.

Everytime a shear pin takes a dump, a little more slop is gained at #1 and #3 points

based on gringeltaube's testing, i disagree with this statement about fitment being a large issue. his tests showed that a 9/32" pin sheared at similar forces in the stock size hole or one that was 'wallered out' or drilled out to 5/16".

his testing also gives us the ability to calculate the actual winch capacity using the OEM pin. earlier in the thread (page 4-ish?) he measures the shear strength of a Saturn pin at 160ft-lbs compared to OEM at ~250ft-lbs, which would easily neuter your winch's capacity by over 1/3rd.

 

[stumps]

I order 6061-T6 aluminum round bar stock from McMaster-Carr and make our pins out of it. It has worked very well in our trucks for many years. We have definitely tested it out with farm equipment recovery operations. They do not have the exact diameter so I buy it a little larger and machine it to the correct diameter. I cut it to the length that allows me to cross-drill each end and put cotter pins in it to retain it in the drive line.
Sometimes a seemingly easy failure like you had is caused by a pin that was partially sheared in a previous operation, then failed more easily later from the damage.

Regards Marti

Hmmm? 6061T6 is softer than the original by quite a bit. 6061T6 has 30ksi shear strength, and as I recall, the original is 2024T361 with 42ksi shear strength.

-Chuck

 

[Bob H]

2 things touched on above

1. possible issue within the winch causing extra drag ( unlikely)

2. shear pin already partially sheared during the last use. (my pick)

 

[stumps]

Hi Travis,

The fitment becomes an issue because when you step on the clutch, the entire drive train relaxes to a neutral position. When you start to release the clutch, any slop is taken up almost instantly, hammering the shear pin. If you are one of those that believes that the clutch should never be slipped, the hammering will be all the harder. Gringletaub's testing was much more static in its application of torque (bicep power), and wouldn't have done much to test this behavior.

-Chuck

 

[dragonwagon]

Allrighty then . I can turn the winch drive by hand , no problem in the winch . Talked to the nephew tonight who worked on these things in the army Said the pin was way weak and they used roll pin . Roll pin is steel but hollow , has the slot down it . Thats what i put in today prior to talking to him just so i could spool my cable back up .

Seems like a roll pin would be weaker then the aliminum pin but i have no facts on that

Right off the bat i had asked if there was home made pins around that dont meet the shear strenght . Sounds like that is a possiblity from one of the post i read here .

Ill try the proper pin when i get them , see from there .

 

[Heavysteven]

Lance
How do you flush the gear oil in the winch? Drain, overfill, drain, and then fill to proper level? I saw the tm about adjusting the winch. How do you clean the brake? Remove the cover spray with brake cleaner maybe?

I would love for some one to post the correct material to buy. Until then guess I will order from Saturn.

 

[m16ty]

Allrighty then . I can turn the winch drive by hand , no problem in the winch . Talked to the nephew tonight who worked on these things in the army Said the pin was way weak and they used roll pin . Roll pin is steel but hollow , has the slot down it . Thats what i put in today prior to talking to him just so i could spool my cable back up .

Seems like a roll pin would be weaker then the aliminum pin but i have no facts on that

Right off the bat i had asked if there was home made pins around that dont meet the shear strenght . Sounds like that is a possiblity from one of the post i read here .

Ill try the proper pin when i get them , see from there .

I wouldn't use a roll pin. while they are hollow, they are made out of some very hard metal (have you ever tried to drill one out?).

Accourding to gringeltaube, a brass bolt is the closest to strength of a USGI pin. This thread- http://www.steelsoldiers.com/deuce/7948-winch-shear-pins.html?highlight=winch+shear+pins really tells you all you ever wanted to know about shear pins.

 

[dragonwagon]

I put the roll pin in today because i had one of the correct size and needed to spool up cable that was wrapped around the bumper . Plan to change it out .

Thanks for the link , man thats a long read ha ha .

 

[blisters13]

I believe the load capacity reduces with additional wraps not because the winch has to pull the line in faster but because the diameter is larger and therefore the ratio between the input shaft rotation to winch cable rotation changes (like gear ratio).