Snowblower Starts But Won’t Move – Fix it now

By: Author John Cunningham. Published: 2021/06/24 at 5:51 am

Moving snow is tough work, but pushing a snowblower is an unimaginable hardship. No, we’ll have to fix it, and you’re in the right place; I’m a mechanic, and I see this problem a ton.

The top five most common reasons a snowblower won’t move include:

1. Drive belt loose/ broken
2. Broken drive bolt
3. Drive cable loose/ broken
4. Friction wheel worn
5. Drive plate contamination

In this post, you’ll learn how your snowblower drive system works, how to diagnose a drive system fault, and how to fix it.

How Snowblower Drive System Works

Most snowblower drive systems are wonderfully simple, easy to access and repair. The basic drive system employs pulleys and a belt to transfer power from the engine to the wheels. It’s this type of system we’ll diagnose in this post.

Some higher-end snowblowers may employ a more sophisticated hydraulic system. It’s known as hydrostatic transmission, and while pulleys and a belt still transmit power, the similarities end there.

We won’t cover the hydrostatic system here for a couple of reasons, it’s far less common, and internal parts for the transmission are not easily available.

Components of the basic snowblower drive system:

• Drive pulleys
• Drive belt
• Drive cable
• Gear selector assembly includes: Hex shaft, gear lever, sliding gear selector, bearings, and bushings
• Friction wheel
• Drive axle assembly includes: Drive axle, gear, gear pin, bearings, bushings, and wheels

And here’s an outline of what each of these components does:

Drive pulleys

A pulley attached to the engine transfers power to an integrated pulley on the drive plate.

Drive belt

Drive cable

The drive cable is a braided cable shielded by a plastic outer. It reaches from the drive control lever on the handlebars to the drive plate.

Gear selector assembly

The gear selector is a beautifully simple solution to gears. Shifting the gear lever slides the selector (with a friction wheel attached) across the spinning drive plate.

Friction wheel

The friction wheel has a very important job. It’s fixed to the Hex axle and transmits power from the spinning drive plate to the final drive.

In addition, it works in combination with the gear selector to change the gear ratio. The friction wheel employs a rubber material to aid traction.

Drive axle assembly

A gear on the Hex shaft drives the drive axle, some snow blowers use a gear coupling, and some may use a chain coupling. The gear is fixed to the axle by way of a bolt or pin. The final components are, of course, the wheels.

Diagnosing Snowblower Drive System Fault

Successful diagnosis means systematically checking over the system and looking for clues as to what’s going on. I have listed the most common failures first, so your problem is likely one of the first in the list.

I deal with all the likely causes below, each with its own diagnostic check. However, you can shortcut the process by doing a little detective work first:

Is the drive lever loose? – If so, suspect a broken belt or drive cable or drive cable adjustment
Does the drive lever feel normal (normal tension)? – If so, suspect possible drive plate contamination, broken axle gear pin, or worn friction wheel
Does the snowblower attempt to move a little? If so, suspect drive plate contamination, cable adjustment, worn friction wheel, worn drive belt, or drive belt tension adjustment
Does the snowblower smell of burning rubber and smoke and not move either forward or back? – suspect belt failure

1 Drive Belt Loose/Broken

Drive belts have a tough job and, for that reason, are a common drive system failure point. Belts can last years, but a poorly-tensioned belt may burn out prematurely.

Common belt faults and their symptoms include:

• Loose – lacks drive or slips under load
• Worn – slips under load
• Breaking – no drive
• Burning – the smell of rubber and possibly smoke
• Glazing – slipping drive when hot
• Contamination – constant slip

Diagnosis

Remove belt cover – To check and diagnose a belt issue, we’ll need to remove the belt cover. The process is as follows:

Check the belt is in place; if not, see fitting new belt below.

Check the belt is tensioned correctly; if not, adjust the idler. See below

Belt tension

Drive belts need to be taught between the pulleys. In order to keep the belt in tension at all times, a spring-loaded arm, known as a tensioner, is employed.

The tensioner is fitted with a pulley that applies all that tension to the belt. A tensioner pulley is known as an idler.

A loose belt causes a slip, and slips cause a lack of drive at the wheels. But slip also causes heat to build in the belt. Excessive heat can cause the belt to smoke and flat spot, but even a little slip can cause a belt to wear out prematurely.

It should be noted most drive belts are not adjustable. In most cases, the spring-loaded tensioner takes up belt slack automatically.

A worn-out or weak tensioner spring, however, can allow a drive belt to slip. In addition, as the belt ages, it gets longer; this, in effect, causes further slip. If in doubt about your belt, replace it. It’s all covered below.

Replacing Drive Belt

Drive belts work hard and eventually wear out. Most belts give you the heads-up long before they actually break. Symptoms include smoke, vibrations, strange noises, slower than normal pace, etc. Yep, they all mean your belt is done, and you’ll need to replace it.

Belt fitting is more awkward than difficult, but sure, you can do it. The correct belt size is crucial to success. An incorrect belt may cause further drive issues. I like to check the belt part number with the manufacturer’s specs as opposed to replacing it with the match of the old belt. The old belt may not be correct.

Remove drive belt as follows:

Fit drive belt as follows:

The refit process is just the reverse of the removal process.

Go ahead now and fit the upper belt keeper and plastic belt cover, refit the spark plug and wire, turn the gas on, and remove the plastic sheet from the gas tank. I think you are ready to play!

2 Broken Drive Axle Bolt

The final drive is driven by the Hex shaft. A gear on the Hex shaft drives a gear on the final drive (axle), causing the snowblower to propel.

The gear on the axle is fixed using a bolt or pin, and they commonly break. The diagnosis and fix are easy – access the axle, verify the fault, and replace the bolt.

The diagnosis process is as follows:

Remove plug wire
Place the plastic sheet over the gas tank neck and refit the gas cap
Tilt blower onto the bin
Remove belly pan

Replace the axle gear fastener as follows:

• Remove any fastener remnants
• Size both the length and diameter bolt required
• Use grade five or eight bolt
• Align the gear hole with the axle hole and fit the new fastener

3 Drive Cable Loose/broken

Drive cables stretch over time, and they’ll need a little adjustment. The most common symptom of a loose cable is a lack of resistance when pulled and of course poor drive or no drive at all. A little adjustment will fix this; see below.

If, on the other hand, the cable has broken, which is common also. The symptoms of a broken cable are more exaggerated. Meaning the drive handle will offer no resistance at all and obviously no drive. This, as you have guessed, means you need a new cable. We cover that below too.

Diagnose loose drive cable as follows:

Adjust drive cable as follows:

Replace The Drive Cable

Replacing the cable isn’t very challenging, but we will need to tilt the blower up onto its bin.

The belt replacing process is as follows:

Turn the gas off and place a plastic sheet around the gas tank

Fitting is the reverse of removal, but you may need to adjust after fitting.

4 Worn Friction Wheel

Friction wheels work super hard. The traction you get at the wheels depends on how well the friction wheel performs. They wear out, crack and disintegrate with wear and age. I replace a ton of them.

Diagnosis is visual, and to access the friction wheel, we’ll need to tilt the blower onto the bin and remove the belly pan.

The diagnosis process is as follows:

Place the plastic sheet over the gas tank neck and refit the gas cap
Tilt the snowblower forward onto the bin

Replacing process is as follows:

Replacing the friction material is the reverse of removal. On reassembly, add low-temperature grease to the Hex shaft. Remember to connect the gear selector rod before tightening the Hex axle fasteners.

5 Drive Plate Contamination

The drive plate supplies the power, so it is super important it’s free from oil and grease. Dirt on the plate will obviously cause the friction wheel to slip.

Contamination is a pretty common problem. It often occurs because excess lubricate or incorrect lube was used on the gears or Hex shaft. Engine oil is another source of possible oil contamination.

Inspect and clean the drive plate as follows:

Place the plastic sheet over the gas tank neck and refit the gas cap.
Tilt the snowblower forward onto the bin.
Remove the belly pan.

Check out the snowblower drive system overview here.

Check for the source of contamination. An engine oil leak will need to be fixed. A drive belt will sling oil onto surfaces, and this problem will reoccur. If the problem was excessive grease on gears or axles, clean off the excess and use a small amount of low-temperature grease (00) instead.