Smoke is never a good look unless it’s a BBQ, but no need to panic it looks worse than it is. I’m John, a mechanic with 25-plus years of experience. Move your machine to the garage, grab a coffee, and very shortly, we’ll have to get this figured out.
Snowblower auger belts commonly smoke because they are loose; adjusting the belt is the usual fix.
In this post, we’ll look at why your auger belt is smoking, how to diagnose the cause, how to inspect the belt for flat spots, how to adjust your belt, and some top mechanics tips to preserve the life of your auger belt.
Smoking Snowblower Auger Belt Causes
A smoking snowblower auger belt can occur for a range of reasons, the usual cause is a loose belt, but often that is not the root cause; it’s just a symptom of the real fault. And sometimes, it’s not a belt fault at all, and in this section, we’ll look at all the suspects before diagnosing the root cause.
Loose Auger Belt
The first on our list is a loose auger belt; a loose belt will allow some slip as the crankshaft attempts to turn the belt, but slip means it’s causing heat, and enough heat causes the belt to burn and smoke.
The go-to fix for a loose belt is to tighten it, and we’ll cover that shortly, but before we do, it’s best to question why the belt came loose in the first place.
Wrong Size Auger Belt
The belt size is critical for proper performance. Sizing a belt correctly can be tricky if you don’t have a belt measuring tool or access to the correct belt part numbers. Incorrect belt sizing is common; the story usually goes like this, – I replaced the auger belt part way through last season, and it worked fine, but now it’s slipping.
A new belt will offer good performance but quickly wear if not sized and tensioned correctly. It is super important to size a belt correctly; we’ll cover that later.
Normal Belt Wear & Tear
Shit wears out; the obvious answer is usually the correct answer. And we can likely diagnose this right now without lifting a wrench. Here goes – If you haven’t replaced your auger belt in the last five years, you can bet it is simply worn out and needs replacing.
If this sound like your problem, you can jump ahead to belt replacement below.
Forign Object Restriction
Foreign object restrictions in the auger, such as Ice, a frozen newspaper, or a dog toy from the yard. Rocks, tree fall, etc., anything that can jam an auger can cause slip at the auger belt. As you know, the auger shear bolts are designed to snap at this point and prevent auger, belt, or engine damage.
But just like links in a chain, the system is only as strong as its weakest component, and in our case, the belt slip suggests our belt is not tight or maybe just worn out.
Correct Skid shoe and Scraper bar adjustments help reduce damage caused by auger strikes, and you can see how to adjust both in the following posts.
Auger Assembly Restriction
An auger assembly consists of various components, all of which require maintenance. They are:
- Auger belt tensioner assembly
- Auger input pulley
- Auger impeller
- Worn shaft and bearing
- Auger transmission
- Auger axle and side bearings
All these components require lubrication, and if they seize or start to bind due to a lack of maintenance, they will cause belt smoke or an engine stall when the auger is engaged.
As you can imagine, a belt should run true from one pulley to the next; a misaligned belt means belt wear and derailment.
The usual cause of misalignment is a damaged/misaligned pulley, but a damaged belt can be a cause too.
An overheating engine can cause smoke but won’t be belt smoke. Instead, the smoke will puff from the muffler; the color is usually white/grey, indicating the engine needs investigation. I include this in our list as it can sometimes be difficult to see where the smoke is coming from.
The usual cause of an overheating engine is a low oil level or incorrect fuel type. Small engines don’t like E15 fuels, and E85 will kill them; they will tolerate E10.
An overfull oil level, carburetor fault, and incorrectly turning over your snowblower (putting it on its side) can all cause smoke, I wrote articles about same, and you can check them out below.
Auger Belt Inspection & Diagnosis
Auger belts work super hard, and they do wear out. They typically last 5-plus years, depending on the belt type, use, terrain, maintenance, and how the machine is stored. I’ve seen belts last less and some a lot longer.
An auger belt should be inspected every year pre-season. No special tools are required to check the belt, an inspection light would be a great help, but first, we’ll need to gain access to the belt, and we’ll do exactly that next after we look at repair safety.
To safely work on your snowblower, remove the spark plug wire to eliminate any accidental risks of the engine starting, remove the key and turn the gas valve off.
Accessing the Auger Belt
We must remove the crankshaft pulley shield to access the auger belt. It’s located between the engine and the bin. Typically the cover is plastic and fastened to the machine with four fasteners.
With the shield removed, we’ll be met with two belts, the belt closest to the bin is the auger belt.
Checking Auger Belt Tension
The handlebar-mounted auger control lever tensions the auger belt. The lever is connected to the auger tensioner arm, which, when activated, swings across and tensions the belt and transfers power to the auger – simple enough, right?
But before we can check auger tension, we’ll need a helper to engage the auger control or use a clamp to hold it on.
We won’t have the engine running at any stage of our checks; there is no need.
First, check the tension of the belt. Use your inspection light and check the belt for signs of damage. Belt damage comes in many flavors, they are:
Stretching or breaking – caused by wear and tear
Blistering – caused by slip (loose belt)
Glazing – polished friction surface caused by slip (loose belt)
Cracking – wear and tear
Stripping – excessive heat or impact
Burning – Loose belt
Flat spots – caused by loose belt and result in excessive vibration
Hard belt – Old age
How do I know if the snowblower belt is worn out?
One of the most common questions I’m asked about snowblowers is belt related, and that’s because belts to a snowblower are like blades to a lawnmower; without belts, our snowblowers are useless.
Snowblowers use two belts, one to drive them forward and back and a second belt to drive the auger.
If you’ve ever tried to push a snowblower with no drive belt, you’d understand why belts are such a hot topic. And that brings us to how to know when it’s time to change the belts.
Here’s what I tell my customers: If your auger or transmission drive belt is over five years old, replace it.
If you experience any of the following symptoms, check those belts:
Transmission drive belt symptoms
- Won’t move forward or back
- Won’t move when engine cold
- Makes a squealing noise when drive engaged
- Slow drive on hills
- Stops on hills
- Smokes when drive engaged
- Drives, but feels jerky
- Have to help push snowblower
- Machine vibrates, and drive feels lumpy
Auger belt symptoms
- Auger won’t move
- Auger won’t move when engine cold
- Auger stops when hits snow
- Auger makes a squealing noise when engaged
- Auger moves, but feels rough
- Auger belt smokes when engaged
- Machine vibrates a lot when the auger engaged
If, on your annual pre-season belt inspection, you find any of the following, change the belt:
- Flat spots
- Hardening of the belt material
Auger Belt Adjustment
As most snowblowers use a similar auger engagement system, your snowblower belt tension can likely be adjusted by simply adjusting the control lever cable, and some allow for idler adjustment at the belt.
The auger control lever cable runs from the handlebars to the auger belt tensioner arm, and if the cable doesn’t pull on the tensioner swing arm hard enough, the belt won’t have sufficient tension and can result in belt slip.
So we need to check the auger belt deflection and, if necessary, adjust the tension. I’ve previously covered this topic in this beginner step-by-step guide with pictures, and you can check it out here – Adjusting auger belt tension.
Auger Belt Sizing
Belt sizing is critical to successfully fitting an auger belt; too big, we’ll have slip and premature wear, and your auger will stop when you hit the really heavy stuff. Fit a belt that is too tight, and you risk damaging auger bearings, and you’ll have an auger that wants to run all the time, no matter what position the handlebar control lever is in.
It is therefore super important that our new belt is the correct size and type.
What size of snowblower belt do I need?
Snowblower auger belt sizes vary by machine make model. In my experience, repairs always run more smoothly with original parts, and ordering original (OEM) makes life a ton easier because we can order our belts using part numbers.
Your owner’s manual will often list the correct belt part number, but it’s just as easy to get the part numbers online so long as you have your make, model, and year of manufacture.
Typically you’ll get that information on the body label.
Alternatively, check your old belt; they often still have the part number legible on the face.
Common Auger Belt Ordering Errors
Buying cheap belts – I know OEM (Original Equipment Manufacturer) parts can be expensive, but I caution against fitting cheap belts; it never works out. You already know belts are super important, especially to a snowblower; poor quality belts mean power is lost through slip, which means premature wear and poor performance. Not only that fitting a belt is an investment of your time, and time is a scarce commodity; who wants to do it twice in the same season?
Sizing with a tape measure – Sizing with a tape measure is possible, but it’s often not accurate enough.
Special belt measuring tools are used to get it right, and you already know getting the size wrong now means you’ll be revisiting this issue again very soon if we don’t get this correct.
Snowblower Auger Belt Care
Snowblower Auger belt care will pay off in the long run. As said, although I recommend replacing the belts every five years as preventative maintenance, I have seen belts last ten-plus years, but that didn’t happen by chance. The owners took care of their machine, which leads us to the question – How do you care for your snowblower belts?
How can I prevent snowblower belt issues?
For auger belt care:
- Check belt for damage
- Check pulleys
- Check and adjust belt tension
- Check tensioner bearing
- Grease auger axle
- Grease auger axle bearings
- Check auger gearbox lube
- Inspect auger for damage
- Inspect the impeller and chute for damage
- Inspect bin, scraper bar, and skid shoes and adjust as needed
- Check shear pins
- Lube & adjust drive control lever
For transmission belt care:
- Check belt for damage
- Check pulleys
- Check belt tension
- Check tensioner bearing
- Lube axle
- Clean drive plate
- Inspect friction wheel
- Lube & adjust drive control lever
- Pump tires
Auger Belt Replacement
Auger belt replacement is something even a beginner can do. You won’t need a ton of tools, and I’ve covered the process step by step previously (link below). I advise changing the transmission drive belt and the auger belt simultaneously, but you don’t have to; for my customers, it makes sense as both belts are located in the same area.
Anyhow, just saying. You’ll find links to both guides below.
- Beginners guide to replacing snowblower auger belt
- Beginners guide to replacing snowblower tarnsmission belt
A common cause of a smoking snowblower is a worn-out auger belt. Loose belts are often the main culprit, but other factors can contribute to the problem.
These include using the wrong size belt, everyday wear and tear, foreign objects obstructing the auger, issues with the auger assembly, belt misalignment, and engine overheating.
We provide tips on inspecting and diagnosing the belt and adjusting, sizing, and replacing it. Regular maintenance and care can help prevent belt issues.
You may find the following posts helpful:
- How long do snowblower belts last?
- Snowblower smells like burning
- Snowblower smoking
- Auger stops in snow
- Snowblower won’t move
- About the Author
- Latest Posts
John Cunningham is an Automotive Technician and writer at Lawnmowerfixed.com.
He’s been a mechanic for over twenty-five years and shares his know-how and hands-on experience in our DIY repair guides.
Johns’s fluff-free How-to guides help homeowners fix lawnmowers, tractor mowers, chainsaws, leaf blowers, power washers, generators, snow blowers, and more.