# Loud noise when blowing snow



## zenny (Nov 1, 2019)

Hi all. I am new to the forum and am looking forward to your comments and to be part of this community. Your assistance and comments are appreciated in advance.

I have a Craftsman Snowthrower Model # 536.886540 which was purchased in 1993. When the engine is idling and the Traction Drive and the Auger Drive is not engaged, the engine does not make a loud noise but is just idling. But when I engage the Auger Drive, I hear a loud noise which goes away until I engage the Traction Drive and move towards the snow and the Snowthrower begins to throw snow. When the Snowthrower begins to throw snow, the loud noise is continuous as the Snowthrower continues to throw snow. I stop throwing snow as the noise seems to indicate that something is wrong.

If any one of you fine people can help me determine what is the problem and what is causing that noise when throwing snow...well, I sure would appreciate your comments.


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## Coby7 (Nov 6, 2014)

If the noise is coming from the engine I imagine a crank bearing.


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## Oneacer (Jan 3, 2011)

Hard to tell, as I don't know where the sound is coming from.


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## Town (Jan 31, 2015)

It appears that at idle there is no problem noise and when you increase engine speed to full throttle there is still no problem noise. The problem noise occurs for a short time when the auger clutch is engaged and goes away. Then you engage the drive clutch and move toward the snow. The blowing of the snow causes the problem noise to be continuous. 

That sounds like the impeller shaft bearing is loose (wearing away the bearing and bearing holder) and making a noise under load or allowing the impeller to touch the housing. But just a guess.

Check for movement (up and down or side to side) in the impeller shaft as a sign of a loose bearing. If the impeller is touching the housing there should be evidence of the contact.


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## groomerz (Feb 7, 2015)

What if engage traction but not impeller. Is there noise


Sent from my iPhone using Tapatalk


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## zenny (Nov 1, 2019)

Thank you all for your thoughts and comments. When I engage Traction Drive there is no noise...only when I engage the Auger Drive. The noise is continuous when the blower starts blowing snow. I will inspect the impeller shaft as recommended by "TOWN". The engine idles with no noise...just when the blower is under load blowing snow. If I can provide more detail to help to solve this problem, please let me know. 

I welcome your continual thoughts and recommendations in the problem solving process. I am so grateful so thank you all again. Zenny


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## notabiker (Dec 14, 2018)

So you hear the noise momentarily when first engaging the auger. Once you start blowing then the noise is continuous.




Check your ribbon gear case for oil. If that's dry then that is most likely the issue. If not then a bearing in there or at the impeller or either end of the ribbon could be causing the issue. Once spinning it quiets down until it gets loaded from the snow. A mechanics stethoscope can help narrow the location down. Harbor freight has them for cheap, just be *VERY *careful when checking the ribbon gearcase so you don't get clothing caught in the ribbons.. Might be a good idea to have a helper pulse the engagement lever while you test areas for noise.


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## zenny (Nov 1, 2019)

Thanks again for your comments. Notabiker...I am a DYI but certainly not as knowledgeable as you. So can you give me some idea as to where the "ribbon gear case" is located on my Craftsman Model 536.8876540 and how to check it for oil? Perhaps my Craftsman has a different name for the ribbon gear box. Thanks

And again thanks for all of your comments. Zenny


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## toromike (Aug 20, 2018)

The "ribbon gear case" is located between the augers. Ribbon is another name for the augers. There is frequently a plug in the front or on top of the gear case that is used to check/add the lubricant. If you have a manual check it for the recommended type of lubricant (oil or grease).

Here is an example of the instructions for a Craftsman 536886480 gas snowblower.
(I couldn't find a manual for your machine.)

The auger gear box is lubricated at the factory and should not
require additional lubrication.
If for some reason the lubricant should leak out, or if the auger
gear box has been serviced, add Lubriplate GR132 Grease
or equivalent. Maximum 3-1/4 ounces, (92 grams) should be
used.

Remove filler plug D (Figure 22 and Figure 23), once a year.
If grease is visible, do not add. If grease is not visible, use a
piece of fine wire, like a dipstick to check if there is grease in
the gear box. Mobilux EP1 and Shell Aldania EP1 are
suitable equivalents.


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## CarlB (Jan 2, 2011)

zenny said:


> Thank you all for your thoughts and comments. When I engage Traction Drive there is no noise...only when I engage the Auger Drive. The noise is continuous when the blower starts blowing snow. I will inspect the impeller shaft as recommended by "TOWN". The engine idles with no noise...just when the blower is under load blowing snow. If I can provide more detail to help to solve this problem, please let me know.
> 
> I welcome your continual thoughts and recommendations in the problem solving process. I am so grateful so thank you all again. Zenny


Sounds like a bad impeller bearing, but if your lucky its only an idler pulley bearing.


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## orangputeh (Nov 24, 2016)

sounds like impeller bearing. too bad you couldn't post a video.

first thing i would do is with the engine off see if there is excess play from the impeller. take off belt cover and wiggle the lower wheelthat the auger belt drives.

also could watch this when engaging auger with engine running. being a 1993 and you had it since new? impeller bearing is 26 years old? 

hopefully that's it. you would be lucky if that's all it is.


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## zenny (Nov 1, 2019)

Again thanks for your thoughts and comments. I do not have a plug that would allow me to add grease to the gear box. I did some troubleshooting and determined that the impeller moves the augers and the gear box and that the worm impeller shaft is working properly..no obstruction or movement to the augers or impeller. So it appears that the bearings are ok.

However, I took off the bottom panel where I saw the friction wheel, disk, the big round pulley that the auger drive belt goes around, traction drive pulley (the big round pulley that the traction drive belt goes around), etc. I noticed the big round pulley that the auger drive belt that goes around could be moved up and down and was loose. Well, I found the attached part (see photos) inside the bottom panel. To see photos go to Gallery and click on Snowblower Key. I hope that works for you. My manual calls it the Key, Square. It appears that this part goes in a slot on the shaft that goes through the center of the big round Auger Drive pulley. I am not able to fit it back into its slot. It seems that the only way I can get this part into its slot on the shaft is to remove the traction drive pulley.

Perhaps this is the source of the noise I am hearing...so, does anyone know how to remove the traction drive pulley (the big round pulley that the traction drive pulley goes around.

I hope that my description makes sense. Your help and knowledge is appreciated. And again thanks for your interests on my behalf. Zenny


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## Oneacer (Jan 3, 2011)

@zenny,

You are correct, it is called a "key" and half of it goes in a long grove in the shaft, and the other half is lined up with the pulleys "keyway". This is a channel in the pulley.

You will see this used all around small engines, very common on holding pulleys, rims, etc. , etc... 

My question would be how did it come out to begin with?

You would remove the bucket on most machines and address the repair that way from the front.


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## Town (Jan 31, 2015)

You do not remove the wheel drive pulley. To access the impeller pulley (the one the auger belts drive) the bucket must be separated from the chassis.

A general idea of how to do that is: 

- The chute usually needs to be removed or the controls between chute and chassis removed. 
- Remove the belt cover and slide the auger belt off the crankshaft pulley toward the bucket. 
- Support the handles (i tie them to a wall) in a somewhat upright position.
- Chock the wheels.
- Remove the one or two bolts each side of chassis near the bucket that holds bucket to chassis. 
- Roll the bucket forward and away from chassis. 
- You now have clear access to the impeller pulley from the back of the bucket.

Good luck.


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## zenny (Nov 1, 2019)

Hi All...and thanks once again for your comments and knowledge. The tip to remove the bucket did give me clear access to enable me to insert the Key into its slot on the shaft. I was also able to tighten the two hex bolts that helped to secure the impeller pulley to the shaft. It’s fortunate that I did this because after running the engine for awhile, the Key vibrated out again but the tightened hex bolts held the pulley secure.

Does anybody know why the key vibrated out of its slot on the shaft? Should I purchase a new Key? Is the old one worn out? Do I even need this Key since it seems that the hex bolts have secured the pulley to the shaft? Did I not insert the Key far enough down the shaft? Do I need to purchase a new impeller pulley? 

By the way, the loud noise I mentioned when I started this tread is gone. So it appears that the Key and tightening the two hex bolts had something to do with the outcome.

Your continued comments and knowledge are appreciated. Thank you all for your help. This is a great forum with great people. Zenny.


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## Town (Jan 31, 2015)

The key is usually held in place with a set screw threaded into the part over the shaft/key and tightened down. Otherwise the key is closed off at each end. Seems you are missing a set screw or an updated design no longer requires a key (?).


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## Oneacer (Jan 3, 2011)

I would check that key, as they should be snug in the keyway … if there is a lot of play, I would replace it, unless the actual key channel has widened by vibration. You need this key in the keyway, as that is what keeps the pulley from just spinning on the shaft.

One of the set screws going through the pully should be screwed down over the key area and the other on the shaft


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## zenny (Nov 1, 2019)

Thanks TOWN and ONEACER for your knowledge...and of course thanks to all who have helped me along the way. I will check the set screws and make sure one is screwed down over the Key area and the other on the shaft. Also, is it possible that the Key channel on the impeller pulley has widened and that I will need a new impeller pulley as well as a Key? 

Zenny


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## Oneacer (Jan 3, 2011)

@zenny,


Highly unlikely, but I suppose possible .......


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## Town (Jan 31, 2015)

zenny said:


> ..... I will check the set screws and make sure one is screwed down over the Key area and the other on the shaft. Also, is it possible that the Key channel on the impeller pulley has widened and that I will need a new impeller pulley as well as a Key?
> 
> Zenny


Sounds like you already have 2 screws, so are they set screws. A set screw is shaped at the end that touches the key or shaft. There is a full circle of metal around the circumference and an indented center, the opposite of a normal screw. The purpose is to allow the set screw to bite into the metal it is to hold. There may also be other designs that bite into the metal. Your key should show circular marks from the set screw.

The key is designed to fit snugly in the keyway of the pulley and shaft and so wear is not an issue, any slight slop will be fixed by the set screw going though the pulley to the key in the shaft and stay tight. The test for a damaged key or keyway is of course to run the key separately into the shaft and the pulley checking for a fit that is snug. Keys are sized for the job and not likely to change, but the width may be different to the height, so orientation is important.

Good luck.


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## tpenfield (Feb 24, 2015)

Lots of possibilities, but without knowing more precisely where the noise is coming from, it is hard to say the cause. A guess would be the impeller bearing is worn.


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## notabiker (Dec 14, 2018)

Okie dokie. If there is no setscrew to keep the key in place then put a drop of high strength loctite on it or in the slot or both and slide it in. Loctite turns into a hard plastic sort of substance once it sets up (probably take a little while if it's in the garage and cold). I've used it on dirtbike and motorcycle sprockets to keep them from wiggling on the shafts so if it can take the abuse of many more ft-lbs of torque without failing then it will surely stop the key from coming out once it's cured.


Also if the pulley moves up and down then that bearing is likely toasted. Best bet is to pull it off and use a caliper or micrometer and measure it and find a replacement on ebay or amazon. When that arrives, use a pick (dental style that mechanics use.. craftsman is one brand) and pull off a sealed lip (go in where it is held against the outer bearing race gently and pry out) and add a bit more grease and reseal and install. Make sure to get sealed bearings so they hold in the grease longer. I recently redid my impeller bearing and ribbon bearings at the outer bucket mounts last winter and did just that. Sometimes the pulley can be a pain to remove or the bearing from the shaft but some emery cloth or file will help.


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## zenny (Nov 1, 2019)

Hello once again and thanks for all your comments, thoughts, and recommendations. I do have set screws. So...I took the impeller pulley off again and noticed that I did not have the Key in its slot far enough to be able to have the set screw touch and hold the Key in place. Thai is why the Key vibrated out. Once I fixed this, I was able to tighten the set screw against the Key and tighten the second set screw against the shaft. The pulley feels secure and in place with no movement at the present time. Started the engine and engaged the auger drive and did not hear a banging loud noise, auger assemblies moved, gear box in order, and impeller pulley having no wobble. I just have to wait for the next snow and start throwing snow and see what happens. Hopefully the Key will stay in place.

For now, I think I have solved my problem thanks to all of you...you are so kind to spend your time helping me. So far so good.

And this project was a blessing in disguise as I discovered that I will have to replace the belts, the friction wheel, and the shear bolts. I think I can do this but I know that you folks will be there for assistance if needed. Your continued comments are always appreciated. Zenny


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## notabiker (Dec 14, 2018)

As long as you don't look at my friction wheel!! The one (I think it's original) on my 1980 TruTest has some cracks along the edges and looks a little rough but still grips great and no chunks missing. 



Shear bolts don't need to be replaced unless they are cracked or broken, they might bend a little but just keep some spares on hand and run them.


Belts is up to you, mine were replaced but I just used some automotive ones and they have some cracks on the inside but haven't stretched. Next time I'm going to the local john deere dealer and finding purpose made ones that are the right length.


All those projects should be easy, it's when you get into replacing bearings that it can involve heat and hammers and swearing.


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