What good are shear pins that don't shear.

[SHOZ]

Out with the snowblower and there was a fairly large branch under the snow. Shear pins didn't shear, one bent. Instead it cracked the gear in half in the auger gear box.

Must be a common failure on the MTD line as the gears are all over the place online. $55 ea though.

 

[Pablo]

People get all worried about failures in heat. There have been more broken gear and such pictures in the last few days than in some time.

Oh, sucks. $55 ouch. Can you get better pins?

 

[SHOZ]

They are the OEM pins. I guess I could use some 12 ga solid copper wire.

 

[volk06]

I hear people talking about switching out the grade 5 bolts for grade 8 all the time at work. I try explaining that the heavier shear bolt can do more damage than good but hey, stronger the better right?????

 

[JTK]

Shoz, it's funny you mention this. I've used my Yardman 24", 7hp snowblower more in the last 4 weeks then I have in the past 5-6yrs.

Anyway... the machine is ~15yrs old and had the factory shear pins in it until this winter. I blew through the factory two and have been using cheap 1/4" bolts as replacements out of a cheap nut/bolt assortment kit I have. I've been through atleast 4-5 of those as well. They bend/break like butter.

The snowplow has been carrying fist sized rocks from the shoulder of the road upstream of me. Ugh.. can't see'em until you hear the bang.

 

[Donald]

At Sears selling tools & OPE stuff I heard of a frozen phone book, frozen Sunday newspaper and grill cover. But these people got away with new shear pins.

The older machines had more cast iron and less stamped steel.

Sears and HomeDepot and Lowes want you to have a protection agreement and then if it breaks for almost any reason, they fix it.

That probably would not be covered by warranty as it was not a manufacturing defect.

 

[SHOZ]

Here is the shear pin.

 

[SHOZ]

I think just some SAE 3 bolts would work better.

 

[The_Jeff]

My work was throwing out some chunks of 1/4" allthread, so naturally I grabbed a bag full. Even has nuts! Blew some of this allthread on my ariens by driving it into my floor jack.

Barely made noise. Busted fine. Fixed with more allthread.

I assume that OP checked to see if the intake augers spin freely and weren't rusted to the inner shafts... Supposedly they need greasing occasionally.

 

[double vanos]

This same mentality says to put a penny under a old timey screw in fuse to stop it from blowing.

 

[SHOZ]

The thing is only two years old. Clean as a whistle inside.

The shear bolts are too strong by far I would say. They make more money off $60 gears than $6 shear bolts I guess.

 

[Donald]

A somewhat similar thing happens with Mercruiser outdrives on a boat. It has a rubber hub that "should" give if the propeller hits something like a rock. If you have an aluminum propeller and hit a rock, the hub will give a little and at the same time the rock chops up the propeller. If you have a SS propeller (which performs better) and you hit a rock, the hub also gives a little, but typically it chews up the gears in the lower unit. The prop may have a few dings.

No impact protection is foolproof.

 

[Warstud]

I didn't know MTD put anything durable on there equipment.

 

[Bror Jace]

Wow, I hit a landscaping timber with my 28" Ariens last year ... didn't throw snow really well after that. It was one of the shear pins. They worked.

Replacements were $2.27 each.

 

[SHOZ]

It's quite a job too to get the auger out. The auger blades all ride on plastic bushings so grease is not that big of an issue.

This is the same set up that they almost all have.

You have to take the belt cover off. Remove 4 bolts that hold the front housing to the rear. Remove the spring loaded cable for engaging the auger belt.

Pull the housing off that at that point is held on by the drive belt. Take off the big pulley on the end of the auger. Remove the bolts holding in the side bearings.

Then the whole thing slides out. The auger blades, bushings and spacers come off. Then crack open the gear case.

 

[KD0AXS]

I had to do the same job. In my case it was the neighbor's snowblower and he didn't want to fix it so he said it was all mine if I thought I could fix it. (He was just going to throw it away) On this one the gearbox was completely destroyed so I had to replace the entire assembly. The gearbox assembly was $150,but I figured it was well worth it when I got the snowblower for free. When I took it apart I noticed he had replaced the shear pins with grade 8 bolts. I replaced the belts while I had it apart and put it back together with the proper shear pins. It blows snow like a champ. This is a Craftsman 8.5 HP 26" blower with the track drive instead of tires.

 

[tom slick]

We build agricultural implements that engage the ground up to 14" deep. Every once on awhile we'll get a call from a client that claims they got a defective shank that broke. The conversation usually goes on to tell us about breaking the supplied grade 5 bolts so they replaced them with "better" grade 8 bolts.
Those "grade 5" bolts we supply are machined to shear at a force less than the failure point of the shank to protect it. It's difficult to tell them that they voided the warranty by replacing those bolts.

 

[jorton]

Picture of snow plow similar to my brothers. It is getting a real work-out these days. He says there's no place to pile up more snow around his circle drive.

 

[SHOZ]

I called MTD today and asked about the shear pins. They said it is a grade 2 steel.

What would anyone recommend as a replacement that would break easier? They are 1/2" in diameter and as you can see they have a cut spot on them.

 

[dave123]

Originally Posted By: SHOZ
I called MTD today and asked about the shear pins. They said it is a grade 2 steel.

What would anyone recommend as a replacement that would break easier? They are 1/2" in diameter and as you can see they have a cut spot on them.


Some people will cut them a little more with a saw.