Snowblower Auger Stops When Hits Snow

A snowblower that won’t move snow is worse than useless. On the upside, this is a pretty easy problem to fix. I’m a mechanic and an auger that lacks oomph is common in my workshop

Snowblower augers commonly stop in snow because the auger drive belt lacks sufficient tension. Adjusting or replacing the auger belt will most likely fix the issue

In this post you’ll learn why your snowblower auger stops in snow and what you can do to fix it right now!

Mower gas cap

Vented Gas Cap

Snowblower Auger Lacks Power

Moving snow is tough work, a misbehaving snowblower just makes the whole task frustrating. I know what it’s like, snow has to be moved, so it's fix the blower or start shoveling. Forget the shovel for now, I think we can fix this.

The auger commonly fails to turn in heavy snow because the belt used to transfer engine power to the auger, is too loose. We simply need to adjust, so that the belt is taught when it’s supposed to be.

Although this is the most likely cause, it’s not the only possible cause. Belt wear is another common cause of poor auger performance, and so we'll cover checking belt condition in this post too.


But first we'll look at the most likely cause, (loose belt) and how you can fix it.

How The Auger Belt Works

Don’t worry, I'll make this super fast. I know, you want to move snow not become an expert snowblower mechanic.

A snowblower is fitted with two belts, both driven by pulleys on the engine crankshaft. The first belt (smaller of the two) drives the wheels, the second larger belt (positioned nearest the auger) drives the auger pulley and consequently the auger assembly.

We are only concerned with the larger belt positioned farthest from the engine, the auger belt.

The auger belt setup commonly employs the following:

  • Belt
  • Pulley on the engine crankshaft
  • Pulley on the auger assembly
  • Tensioner arm with adjustable idler pulley
  • Auger lever (at handlebars)
  • Auger lever cable/rods

With the belt assembly at rest, the auger belt is loose and no power is transferred to the auger.

Pulling and holding the auger lever causes the tensioner arm with attached idler pulley to apply tension to the belt consequently transferring engine power to the auger.

Simple setup, right?


Next we’ll need to access the belt and check belt tension.

Accessing Snowblower Auger Belt

First we need to make working on our snowblower safe and to do that we’ll need to remove the plug wire. Pull and twist to remove, set it away from the spark plug.

The process for removing the belt cover is as follows:

  • Remove two fastener bolts either side (10mm or 13mm)
  • Wiggle it loose and pull straight upwards
  • Set cover and fasteners aside

Checking Snowblower Auger Belt Tension

With the cover removed, go ahead and identify the auger belt. Remember it’s the larger belt of the two, positioned closest to the auger.

Notice also the tensioner arm with attached idler pulley. (Idler pulley is so called, because it’s sole function is to deflect the belt - idler)

A helper would be great about now, if not use a clamp to hold the auger lever on at the handlebars.

You must remove the plug wire before checking belts, Did You?

With the auger lever applied, check tension on the auger belt. Deflect the belt with your finger at its longest throw and access deflection.

Does it look loose? About a 3/16 inch (5mm or so) deflection for every 12 inch (300mm) span (pulley axle to axle). Don’t sweat this detail, if your instinct is, it’s loose, then it’s loose)

If it is loose, it will require adjustment. But before we go to the trouble of adjusting the belt, let's check it’s general condition first.

Checking Auger Belt Condition

Most snowblower auger belts are V type belts. So called because of their shape. Belts work really hard and are often forgotten about until there's a problem.

Check your belt and replace it if it looks spent. Typically as a belt wears it suffers from one, or many of the following:

  • Stretching – Wear and tear
  • Breaking – Auger assembly issue
  • Glazing – Polished friction surface caused by slip
  • Cracking – Excessive heat
  • Stripping – Excessive heat or impact
  • Burning  – Excessive tension
  • Flat spots – Caused by loose belt and results in excessive vibration
  • Hard belt – Old age

As the V aspect of a V belt wears, it allows the belt to sit further into the V of the pulley. This causes the belts inside diameter (ID) to become larger. The larger ID causes less tension on the belt

Less tension on a belt (loose) causes slip and heat which causes a belt to wear prematurely or glaze.

One of the best ways to improve snowblower performance is to replace the belts. Many snowblowers don’t see a ton of action and while the belts may not be worn they do get hard with age and a hard belt causes slip.

In the workshop I routinely examine and replace the drive belt while replacing the auger belt

Adjusting Auger Belt Tension

Adjusting belt tension takes little effort and only a few wrenches. The idler pulley is fitted to the tensioner arm on an adjustable axle. Meaning when we loosen its fastener, we can adjust the pulley relative to the arm.

The process is as follows:

  • Release the auger lever at handlebars
  • Mark current idler pulley axle location (use paint)
  • Loosen the idler fastener (2 x 13mm or 14mm usually)
  • Slide the pulley towards the belt (Note: belt must remain loose at the engine pulley after adjustment)
  • Go ahead and tighten the idler fastener

Test by applying the auger lever at handlebars.

The belt is correct if:

  • The belt is taught when the lever is applied
  • The belt is loose at engine pulley when auger lever is released

Replacing Auger Belt

Replacing the belt isn’t as tough a job as you might imagine. You already know how the setup works. Understanding what will aid in the replacement procedure.

Mission critical is belt length, getting this wrong will mean you'll be back visiting this problem soon if not immediately.

A belt that's too long will either not work at all or as you know, slip. A slipping belt may cause the belt to burn and smoke

A belt that's too short is bad also. A short belt causes the auger to turn even though the lever is in the off position. It's not uncommon for this problem to present only when the engine pulleys warms up.

Ordering Belts

All belts are coded and also sport and measurement. I don’t advise measuring the belt, that rarely works out. It’s best to check with the manufacturer and order by code.

I like to fit the best quality Kevlar belt I can because I don’t want to come back and visit this again any time soon.

It is possible to read the code from the old belt. However, be mindful, unless you know the machine, a previous repairer could have fitted an incorrect belt. (bitter experience and I don’t want to talk about it)

Confident you have the correct belt at hand, the replacement process looks like this:

  • Turn gas tap off
  • Remove plug wire
  • Cover gas tank neck with plastic
  • Remove belt cover (as above)Lever tensioner/idler back and turn auger belt off crankshaft pulley
  • Turn snowblower upwards onto auger bin
  • Remove belly pan
  • Remove auger pulley belt guide
  • Apply and hold auger lever at handlebars (releases auger brake)Remove belt

Fit the new belt as follows:

  • Feed new belt from belly pan side
  • Fit around the auger pulley
  • Release handle bar auger lever
  • Fit auger pulley belt guide
  • Fit belly pan
  • Place snowblower on wheels
  • Lever tensioner back and turn belt onto crankshaft pulley
  • Release tensioner
  • Check and adjust belt tension as per above
  • Replace belt cover
  • Turn gas on
  • Plug wire on
  • Remove gas tank plastic

You may also consider replacing the drive belt while replacing the auger belt. It is only a little extra work and won’t cost a ton.


Auto Technician and Writer at Lawnmowerfixed | Website

John Cunningham is an Automotive Technician and writer on I've been a mechanic for over twenty years, I use my knowledge and experience to write "How to" articles that help fellow gear-heads with all aspects of mechanical repairs, from lawn mowers to classic cars.