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Discussion Starter #1
Hi,

A neighbor dropped off a craftsman 536.887992 to me the other day with two sheared impeller roll pins. When I took it apart, I noticed a severely warped auger pulley that also had a dent in the edge causing the pulley to pinch the belt in that area.

I figure that this may be what caused the roll pins to shear as this would likely keep the belt from slipping and thus when the impeller was over loaded, the pins were the weakest point.

I replaced the pins and have a pulley and belt on order but was wondering what could typically cause such a severe warping of the pulley. I want to not only fix the problem but prevent it from happening again.

Thanks
 

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Maybe someone once tried to pry it for some reason, with a pry bar ?
Is he the original owner?

Do you have a picture?
 

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Discussion Starter #3
That's what I thought. When I pulled it off, it came off like butter. He said he's had it serviced once by Sears. I figured if they wouldn't do that but what do I know? It totally looks like someone tried to pry it off with a bar or something but I figured Sears would have a better method for their own machine.
 

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Discussion Starter #5
I agree. I was having a hard time believing that someone, with supposed expertise, would do that to the pulley, put it back on and give it back to a customer. Maybe I'm just naive.

So I will replace the pulley, belt and call it a day.
 

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I guess he is the original owner?
 

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Unless he did it somehow and is embarrassed to admit to it I guess Sears did it then?
I can't think of anything else to "warp" it?
You would think if somehow he jammed the blower up either the belt would pop or something else would break before the pulley got bent?

I can only imagine what "warped" looks like, as you posted no picture for anyone to look at.
Maybe if you posted a picture someone would see something?

The pulley in question is the #480 in the link I posted?
If so what condition was the key for it?

Here is the auger housing link, AUGER HOUSING Diagram & Parts List for Model 536887992 Craftsman-Parts Snow-removal-equipment-Parts | SearsPartsDirect
 

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Discussion Starter #9
You're confirming what was going through my head. I tried to bend the pinch out with a pair of pliers but that steel was tough. No way a belt incident could result in such deformation. Unfortunately, I don't have the machine here to take a picture. While we're waiting for the new pulley, he wanted the machine back to do some minor blowing, which I advised against. The pulley break makes an awful clank when you back off the auger lever. I will, however, get the machine back once the pulley comes in and I'll post a picture.
 

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Discussion Starter #10
So I installed a new input pulley and belt. I've also attached some photos of the old pulley showing the damage and overall lack of true-ness. When I was taken this one apart I noticed scuffing on the tension pulley arm. My guess is that the pulley hitting the arm is what caused the dent.

I also noticed that when I engage the auger and watch the pulley, it appears as if the shaft is moving in and out a bit causing the pulley to move toward and away from the impeller housing in the front and the tension pulley arm in the rear.

When I had it apart, there was no play in the bearing at the housing where the shaft comes through so it seemed fine to me. Is this movement normal?

Because it appears that movement allows the pulley to come toward and away from the tension arm and may have caused the damage.

The last poster make a good point that someone may have tried to pry the pulley off but I noticed the damage is on the opposite side of the pulley, the tension pulley arm side.

Another question I had, can over tension cause the pulley to warp?

I just don't want this to happen again to the new pulley.

Thanks so much for all the help.
Lefty



 

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If the impeller shaft is moving forwards-backwards then the bushings / washers in the front gearbox are worn.
 

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That's what I thought. When I pulled it off, it came off like butter. He said he's had it serviced once by Sears. I figured if they wouldn't do that but what do I know? It totally looks like someone tried to pry it off with a bar or something but I figured Sears would have a better method for their own machine.
sears does not service what they sell the work is contracted out
 

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Discussion Starter #15
Makes sense. I think Shryp is right on the money. Something in the gearbox is hosed causing the shaft to move to and fro....throwing the pulley into the tension arm and causing the damage. I see scuffs on the tension arm right about where the pulley would make contact. And as I had mentioned, I can see the shaft moving while the auger is engaged.
 

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Discussion Starter #16
So...

I think classiccat is correct too. I had this apart again and looked closer at the impeller shaft. I do have some run-out which is visible to the naked eye when spun by hand....so I have a theory and a few questions.

1. The impeller shaft became bent which caused the bushings / flange etc in the gear box to go bad allowing the shaft to then move in and out, tossing the input pulley into the tension pulley arm and damaging the pulley.....ya? Or maybe a didn't happen in that order.

2. How much, if any, run-out is acceptable on the impeller shaft?

3. Would it be crazy to use the machine at all in this condition? Worse case scenario I can imagine, barring any sort of physical injury to the operator, is that the whatever may be broken at the gear box gets inside and chews up the brass gear. Or the pulley gets mangled again?

Only reason for question 3 is that this is my neighbor's machine. I'm working on it because I enjoy it and I am not charging any labor. I have a full time life and this would most likely be a week long project for me to replace broken parts in the gearbox, impeller shaft, etc. Not to mention the delay for shipping since parts have been hard to come by locally. We have more snow on the way in a couple of days.

The only reason the machine found me is that it sheared the roll pins on the impeller, which I assumed was from the mangled pulley pinching the belt under heavy impeller load, which may be wrong. Anyway, point being, he has been using it with the warped mangled pulley for some time and if it wasn't for the roll pins, would have kept on using it.

Thanks very much
 

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My Ariens was like that and I opened up the gearbox just to check on the gears and the grease in there. Turns out the grease was fine and it wasn't needed, but I felt better checking. The collar on the front bushing where it rubs on the impeller shaft gear was worn allowing the movement. I just put 2 small washers between the front bushing and the case to push the bushing tighter against the impeller shaft and that took care of my movement.
 
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