Cub 3x Snowblower/HD Shear Pins

I have a cub three stage snowblower that eats shear pins like candy, I went through two dozen of them last year. I checked with cub and they say they have a new shear pin that they sell for the third stage impeller’s but they cost six or seven dollars apiece, or in a kit with two of the good ones and four cheapies for $18.99. These sheer pins have a hex head on them like a bolt, but they still have the pin fastener in the bottom. They say A on the head of the pin. Does anybody know what that A stands for, and where to get some? $18.99 for two of them and four cheapies is ridiculous. I do know that it’s not a grade 8 like a lot of people think, those are way too hard and will break your shaft.

HRG (Hot Runr Guy) is you guy for all things metal. Shoot him a PM.

Thanks ,good idea.

Cub Cadet is known for charging the customer for their poor engineering.

How about a 1/4 inch brass bolt? Soft enough?

OP are you taking in any debris other than snow?
I’m sure you know the shear pin is designed to shear when enough resistance is encountered, thus preventing damage inside the gearbox which would be a much more costly/time consuming repair.
If you’re not pulling in rocks, newspapers (one of the worst to get out), sticks or other debris, then you should probably try the upgraded Cub pins and see if they are satisfactory. You do not want real soft metal, it needs to be brittle enough so that it will snap off and not bend before shearing – the fracture lines in shear pins are to ensure the pins shear at the correct location. You could try alternate brand pins if they have the fracture line in the correct location, but there’s no way to know their shear strength – could be more, could be less than the Cub pins.
I hate that feeling of being held over a barrel by manufacturers, but in your case, the extra expense is better than severe damage that could take a long time to get parts for in the prime snow season.

My local dealer actually gave me a pack of the 6 pins yesterday, 2 good-4 regular pins. I put both good ones in and broke one. The three stage gimmick is basically just another plate like the second stage with about an inch longer collar on it. It appears to me that when going through heavy snow, and I’m always in the lowest gear, that the front stage gets stuck in the snow and snaps the pin. I know that if I’m going through ICE and sticky slop like the snow plows leave that there’s a good chance they’re going to break but I go very very slow through those areas and usually go about a foot at a time and let the shoot clear. And I never take the whole 26 inch swath, I always do about half passes in those areas. But still broke one.

mojo wrote:

newspapers (one of the worst to get out),

I once ran over a frozen bath towel–no idea where that came from. That was a major PITA to get out!

Ralph Wiggum wrote:

<div class=”d4p-bbt-quote-title”>mojo wrote:</div>
newspapers (one of the worst to get out),

I once ran over a frozen bath towel–no idea where that came from. That was a major PITA to get out!

I got a frozen phonebook that fell outside the neighbor’s mailbox wedged inside the impeller last year. That was a major PITA too!

A few years ago I found out the FASTEST way in the world to wrap up an extension cord

I had a 50′ cord coiled up in 1.75 seconds lol

B-man wrote:

A few years ago I found out the FASTEST way in the world to wrap up an extension cord

I had a 50′ cord coiled up in 1.75 seconds lol

Kinda like wrapping a ski rope in a jet ski impeller…

Sheared a pin on my Cub 3X and the pin stayed stuck in the shaft. It took an hour of progressively larger hammers to drive it out with a punch. Should have drilled it out but it was tight quarters. Never had trouble before or since. They usually simply fall out. PITA.

I got a frozen phonebook that fell outside the neighbor’s mailbox wedged inside the impeller last year. That was a major PITA too!
[/quote]

Ha! I had the same thing happen once. Stopped the blower right in its tracks. Was a lot of work getting it all cleaned out

Debris isn’t causing my problem, poor engineering is.

Well, since everyone is sharing stories, I have one- I once did my neighbor’s driveway when I used to live in Hastings and I was working from home, knowing full well he doesn’t own a snowblower and would find himself shoveling out 15 inches of heavy snow.

While blowing out his driveway for him, I hit a buried newspaper which shredded itself into a million pieces all over his driveway and yard. To make matters worse when it happened it caught me off guard and I swerved the blower into the side of his work van, leaving a big scratch.

When he got back from out of town the next day we shared a good laugh (thankfully).

I just talked to a retired railroad guy that knows metals very well. I had 3 different pins and he told me what each was. I didn’t have one of the new Cub ones they sell for $6 apiece as it was in my blower. I found an online Cub dealer that sold me 10 of the new genuine Cub packaged pins for $13 and free shipping. When I get one Ill show it to the friend to identify. The 3 I had were 2 grade 2 and a grade 3 (I didn’t know there was a grade 3 but he did). I hope the Cub ones are grade 5. He says DO NOT use grade 8, but says most auto stores should have grade 5, I’ll let you now. Thanks HRG for your help, I’ll PM you when these new ones come and see what my railroad friend says. I was amazed at how he identified the 3 I had so quickly.

Matt Moen wrote:

<div class=”d4p-bbt-quote-title”>B-man wrote:</div>
A few years ago I found out the FASTEST way in the world to wrap up an extension cord

I had a 50′ cord coiled up in 1.75 seconds lol

Kinda like wrapping a ski rope in a jet ski impeller…

Was it plugged in?

Buy a Toro mine has never broken a shear pin.

3rdtryguy wrote:

I just talked to a retired railroad guy that knows metals very well. I had 3 different pins and he told me what each was. I didn’t have one of the new Cub ones they sell for $6 apiece as it was in my blower. I found an online Cub dealer that sold me 10 of the new genuine Cub packaged pins for $13 and free shipping. When I get one Ill show it to the friend to identify. The 3 I had were 2 grade 2 and a grade 3 (I didn’t know there was a grade 3 but he did). I hope the Cub ones are grade 5. He says DO NOT use grade 8, but says most auto stores should have grade 5, I’ll let you now. Thanks HRG for your help, I’ll PM you when these new ones come and see what my railroad friend says. I was amazed at how he identified the 3 I had so quickly.

Are there markings like these on the head of the pins? https://www.mudgefasteners.com/news/2021/1/24/deciphering-bolt-head-markings

HRG

Not on there, capital A on the so called stronger Cub pins.

Mark Uidenich wrote:

Buy a Toro mine has never broken a shear pin.

I’d never broken one on my Ariens till we moved to a house with landscape rock near the driveway. Now, I go through quite a few.

Better a shear pin than something expensive. I just have a bag of spares handy in the garage.

I never broke shear pins either on a traditional blower. These 3 stage are a completely different animal. Here’s a picture they shows the 3rd stage and the two shear pins that break are in the flat discs that face forward. The theory is they shred the chunks of snow so it can throw easier. The augers on each side push snow into these two “accelerator disks”.Weird new design but it works well except for the shear pin problem that hopefully stronger pins will fix.

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I’ve been running a cub 3 stage for 3 or 4 years. Never had an issue.

Mark Uidenich wrote:

Buy a Toro mine has never broken a shear pin.

The newer Toro’s don’t even have shear pins, its one of their selling points and part of the reason I bought mine. Funny thing is I was looking at the Cub Cadet 3 stage a few years ago and all the reviews about constant shear pin replacements turned me away. Ended up finding a couple that was moving south in the spring and got a Toro 1028 that had been used 3 times that winter for half price

I’ve broken a few in my Ariens 2 stage. Most times when the end of the drive gets plowed in with heavy packed snow and ice. But I would rather change a softer pin. Then put the damage to the shaft, elongating the hole with a harder pin. If you absolutely need a harder pin. I’d make sure to stay with one designed for your snow blower. Like mowers. Most small engines are produced with Chinese machine work. They don’t take stress well.

Make sure the bolt holes have not become elongated or egg-shaped because of multiple breakages. Having extra slop with an elongated hole allows momentum to be built up and makes it easier for the spinning shaft to “guillotine” off the bolt.

I also have seen where due to sloppy manufacturing tolerances, there is significant variation from bolt to bolt in the diameter. Again, if you have slop or play, that shear bolt will break much more easily, you wouldn’t think a few thousandths would matter, but it does when something is spinning at x thousand RPMs.

You can buy different grades of bolts online. Personally, I’d start at grade 2 and move up from there if necessary until you find the grade that doesn’t break in conditions where you’re breaking the factory bolts. I’ve gone through this before and with a brush hog that ate shear bolts. Industrial hardware suppliers also stock multiple grades of bolts so you can get the more unusual grades.

The Cub Cadet 3 stage units are notorious for this issue, BTW. I looked at one for a neighbor last year, same issue he couldn’t keep shear pins in it and thought a bearing was bad or a shaft was bent. Nope, just a bad design and IMO a solution in search of a problem. If you think you need a “third stage” you are probably using a snowblower that is too small for your needs in the first place.

Just a thought I had when I finished snowblowing today and looked at the shear bolts in snowblower:
Maybe you are over torqueing the bolts at installation and prestressing them causing them to fail more easily.

I’ve only taken out one pin on my cub cadet in 18 years and it was a hockey puck in my neighbors drive.
It has been incredibly reliable. Never broken and still runs like the day I bought it. Changed the belts once. 7hp two-stage.

sticker shock
I just looked up the shear bolts thru Grainger, for my Ariens walk behind thrower.
Shear Bolt Kit, For Use With Ariens Deluxe/Pro Snow Blowers Web Price

$55.07 / pkg. of 3 These are 5/16 diameter by 2 inch long.

Thru Amazon, I can get 20 of these shear bolts for $22 including shipping.

Huntindave wrote:

sticker shock
I just looked up the shear bolts thru Grainger, for my Ariens walk behind thrower.
Shear Bolt Kit, For Use With Ariens Deluxe/Pro Snow Blowers Web Price

$55.07 / pkg. of 3 These are 5/16 diameter by 2 inch long.

thats because its grainger. there $7.90 for a 3 pack on amazon