# Too much tension on auger belt?



## ssiddall (Dec 15, 2016)

I have a new Craftsman 247.881980 snow blower that keeps throwing the belt very quickly after engaging the auger fully. It *appears* that the pulley is pushing the belt off the drive pulley. (It looks like the belt is twisting.)

I'm guessing this is a rare issue as most auger belt problems are because of a belt that's too loose. Has anyone had this issue? 

Also, the pulleys are not aligned. I'm thinking this is really Ok as the tension on the belt, if adjusted correctly, will keep the belt on the pulleys. Correct?

Thanks for any feedback.


----------



## jtclays (Sep 24, 2010)

Pulleys not aligned is not correct. "New" take it back. New to you..... did it ever work correctly, or is the pulleys out of alignment only after working on the belt?


----------



## bad69cat (Nov 30, 2015)

Agree - the alignment is off somehow I bet....... check that the right belt is on there (rides deep in the pulleys) and that the engine pulley is in line with the auger pulley when the lever is tight. You may have to loosen the engine bolts and align it a touch if not. That looks like one that I have and the pulley actually tilts quite a bit when it's going in/out of operation. I had a hard time getting it right when I re-powered it with a Honda...... same deal, it kept throwing belts. It was very finicky about staying aligned.

http://www.searspartsdirect.com/mod...odelSearch&q=247.881980&searchTerm=247.881980


----------



## jtclays (Sep 24, 2010)

Now that I see the schematic (thanks bad69cat), I remember doing some maintenance on a neighbors.
This is the one with no friction drive, just a simple lawnmower tranny, single forward, no belly pan?
On those they have a couple weak spots to check. The engine sheaves (small pulleys on crankshaft) are 2 piece, make sure the center bolt/washer is tight on end and the sheaves have not lost their integral key. The auger pulley, (bigger lower one) has a bolt with washer holding it to the impeller shaft. Make sure it's tight also, but need to make sure the little dogs line up into the slots in the middle of the pulley face. If it was put on wrong and the dogs are not aligned or sheared, the belt will never drive correct. Also, if you or someone else put a belt on through the belt inspection cover, flip the machine up and look underneath. Make sure they didn't route the belt around the brake bracket or the keeper stud. The belt should be sitting inside of everything and only on the pulley groove.


----------



## ssiddall (Dec 15, 2016)

jtclays said:


> Pulleys not aligned is not correct. "New" take it back. New to you..... did it ever work correctly, or is the pulleys out of alignment only after working on the belt?


This is a new blower and I was lucky to get it. I could return it, but then I'll be left with nothing and I think I got it for a pretty good price. (There are no more in stock in my area.) I'm pretty handy, so I'd like to fix it if it's a minor fix. 

I can't believe that the pulleys are misaligned from the factory, but I guess it's possible. I put the belt back on and slowly turned the pulleys and found at some point the belt starts twisting, and thus the belt gets thrown.


----------



## ssiddall (Dec 15, 2016)

bad69cat said:


> Agree - the alignment is off somehow I bet....... check that the right belt is on there (rides deep in the pulleys) and that the engine pulley is in line with the auger pulley when the lever is tight. You may have to loosen the engine bolts and align it a touch if not. That looks like one that I have and the pulley actually tilts quite a bit when it's going in/out of operation. I had a hard time getting it right when I re-powered it with a Honda...... same deal, it kept throwing belts. It was very finicky about staying aligned.


Thanks bad69cat. I think it's a alignment problem too. Loosening the engine bolts will allow me to get the pulleys aligned? I'm new to snow blowers...


----------



## jtclays (Sep 24, 2010)

Did you tilt it up and watch from underneath? Since it is new, try tilting it forward as if you were going to put it on it's nose and watch the seam between bucket and the tractor. Maybe the bolts on the sides were not tightened properly. Here's a video that shows the brake assembly and keeper stud I mentioned.
Clearly seen around the 15:05 mark. Notice how the belt is inside those two things.





You can see the dogs and pulley face here in this videos also.


----------



## ssiddall (Dec 15, 2016)

jtclays said:


> Now that I see the schematic (thanks bad69cat), I remember doing some maintenance on a neighbors.
> This is the one with no friction drive, just a simple lawnmower tranny, single forward, no belly pan?
> On those they have a couple weak spots to check. The engine sheaves (small pulleys on crankshaft) are 2 piece, make sure the center bolt/washer is tight on end and the sheaves have not lost their integral key. The auger pulley, (bigger lower one) has a bolt with washer holding it to the impeller shaft. Make sure it's tight also, but need to make sure the little dogs line up into the slots in the middle of the pulley face. If it was put on wrong and the dogs are not aligned or sheared, the belt will never drive correct. Also, if you or someone else put a belt on through the belt inspection cover, flip the machine up and look underneath. Make sure they didn't route the belt around the brake bracket or the keeper stud. The belt should be sitting inside of everything and only on the pulley groove.


Thanks for the input jtclays. I'll check this stuff when I get home.

Is it common for new blowers to have problems like this?


----------



## jtclays (Sep 24, 2010)

No. Depends who puts it together. If you route the belts wrong or don't tighten the bucket to tractor bolts correctly on a $4000 Honda, it won't run right either:icon_smile_big:


----------



## ssiddall (Dec 15, 2016)

Thanks for the videos! Extremely helpful! (Goes without saying, I suppose.  )


----------



## ssiddall (Dec 15, 2016)

jtclays said:


> Did you tilt it up and watch from underneath? Since it is new, try tilting it forward as if you were going to put it on it's nose and watch the seam between bucket and the tractor. Maybe the bolts on the sides were not tightened properly. Here's a video that shows the brake assembly and keeper stud I mentioned.
> Clearly seen around the 15:05 mark. Notice how the belt is inside those two things.
> 
> https://www.youtube.com/watch?v=zZD49eaGcqg
> ...


What are "dogs"?


----------



## ssiddall (Dec 15, 2016)

So I learned a couple of things. 
1. If I remove the upper side bolts holding the bucket and the tractor, I can pull them apart slightly and the pulleys then line up. 

2. I think the auger idler pulley is trying to push too hard. There is a point at which (as I pull in the auger handle) the idler pulley stops pushing on the belt and begins to "twist" a bit. This, I'm sure, is a contributing factor in the belt coming off. I'll just adjust the idler pulley back a bit.


----------



## jtclays (Sep 24, 2010)

ssiddall said:


> What are "dogs"?


At around the 2:14 mark you'll see the pulley has slots and the impeller hub has what I refer to as "dogs" that line up to fit the slots. They are more correctly probably called cogs or teeth. I have seen friends try to put these back together with them not engaged. It causes the pulley to be out of alignment, but if you crank on the bolt it will also work for awhile until the belt throws:facepalm_zpsdj194qh
Sometimes those idler arms are bent or tweaked out upon assembly. If you take the belt off and use the auger handle to move it, you may notice it tracks crooked. You can "tweak" it back straight slightly. The cable system and handle can also bend the idler arm if the belt was routed wrong (which causes the belt to be "too short" and thus putting excess pressure on the idler arm). It's just stamped metal


----------



## bad69cat (Nov 30, 2015)

Yeah - make sure you are checking the alignment with the lever pulled (in operating position) that will hep you guage what's not lining up....... but knowing the the pulleys are riding int he correct place will eliminate that as part of the trouble. When you have it all back together you could have a helper rotate the motor and hold the lever while you watch how the belt tracks....... that may help to see whats really going on in slow motion.


----------

