How to Maintain a Snow Blower
To maintain a snow blower, change the oil with the engine warm, replace the spark plug, check and replace shear pins, lubricate the auger and chute, check belt tension, add fuel stabilizer, and test-run the machine for 5 minutes. Do this every fall before the first snowfall.
- Time
- 30 min
- Frequency
- every fall (before snow season)
- Difficulty
- medium
- Cost
- $15
What you'll need
- Socket wrench set
- Oil drain pan
- Spark plug wrench
- Grease gun or spray lubricant
- Shop rags
The steps
- 1
Change the oil with the engine warm
Start the snow blower and let it run for 2 to 3 minutes to warm the oil. Shut it off, place a drain pan underneath, and remove the drain plug. Let the oil drain completely. Replace the drain plug and refill with the oil type and amount specified in your manual (usually 5W-30 for cold-weather equipment). Check the dipstick.
- 2
Replace the spark plug
Remove the spark plug wire. Use a spark plug wrench to remove the old plug. Gap the new plug to the spec in your manual (typically .030 inches). Thread the new plug in by hand, then snug with the wrench. A fresh spark plug ensures reliable cold-weather starting when you need the machine most.
- 3
Check shear pins and keep spares
Inspect the shear pins on the auger shaft. These are small bolts designed to break if the auger hits a rock, newspaper, or frozen object, protecting the gearbox from damage. Replace any that look bent or partially sheared. Buy a pack of spares and keep them in the snow blower's storage area. Never substitute a regular bolt for a shear pin.
- 4
Lubricate the auger and chute
Apply spray lubricant or silicone spray to the auger shaft, chute interior, and chute rotation mechanism. A lubricated chute throws snow farther and does not clog as easily. Grease any zerk fittings on the auger shaft with a grease gun. Check your manual for all lubrication points.
- 5
Check belt tension
Inspect the auger drive belt and the wheel drive belt (if equipped). Look for cracks, fraying, or glazing on the belt surface. Press the belt with your thumb — it should deflect about half an inch. A loose belt slips under load and reduces throwing distance. Replace worn belts before the season starts.
- 6
Add fuel stabilizer
Pour fuel stabilizer into the gas tank according to the product's dosage. If the tank has old fuel from last season, drain it first and start with fresh gas. Ethanol-blended fuel degrades quickly and gums up carburetors. Stabilizer keeps fuel fresh between storms when the machine may sit idle for weeks.
- 7
Test-run for 5 minutes
Start the snow blower and let it run for 5 minutes. Engage the auger and drive controls briefly. Listen for unusual sounds. Check that the chute rotates smoothly and the deflector adjusts properly. This confirms everything works before the first storm, not during it.
Pre-season service prevents mid-storm breakdowns
A snow blower sits unused for 8 to 9 months of the year. When the first storm hits, you need it to start on the first pull and run without issues. That reliability comes from 30 minutes of fall maintenance, not from luck.
The most common snow blower failure is a no-start caused by stale fuel and a fouled spark plug. The second most common is a clogged chute from dried-on snow residue and lack of lubrication. Both are entirely preventable. An oil change, fresh spark plug, lubrication, and fuel stabilizer address every major failure mode for under $15 in parts.
Shear pins are a safety feature
The shear pins on a snow blower auger are sacrificial by design. They are made from soft metal that breaks at a specific torque threshold. When the auger hits a rock, a frozen newspaper, or a buried garden hose, the shear pin snaps and the auger stops spinning. This protects the gearbox, which is the most expensive component in the machine.
Never replace a shear pin with a regular bolt, a cotter pin, or anything harder than the original pin. A hardened bolt will not break under impact. Instead, the full force transfers to the gearbox, stripping gears or cracking the housing. Gearbox repair costs $150 to $400. A pack of 4 shear pins costs $5 to $8.
Keep a handful of spare shear pins and the correct wrench in a bag taped to the snow blower handle. When a pin breaks mid-job, you can replace it in the driveway in 2 minutes instead of stopping for the day.
Chute lubrication prevents clogging
Wet, heavy snow sticks to bare metal. If the inside of the chute and auger housing is dry and rough, snow accumulates and eventually blocks the chute completely. A clogged chute is frustrating and dangerous — the temptation to clear it by hand leads to serious injuries every winter.
Before each use, spray the inside of the chute and the auger housing with silicone lubricant or a non-stick spray. The slick surface lets snow slide through without sticking. Reapply during long sessions if clogging starts to occur. At the end of each use, run the auger for 30 seconds with no snow to clear residual buildup.
Always use the clean-out tool (the plastic stick that came with your machine) or a wooden broom handle to clear a clogged chute. Never reach in with your hand, even with the engine off. The auger can have stored tension that releases when the clog breaks free.
Fuel management
Snow blowers face a unique fuel challenge. They run hard during a storm, then sit idle for days or weeks until the next one. Ethanol-blended fuel begins degrading in 30 days. A snow blower that runs great during a December storm can have carburetor problems by a late January storm if the fuel was not stabilized.
Add fuel stabilizer to every tank, not just the last one of the season. Treat the fuel when you fill the can at the gas station. This way every fill-up is protected. A 32-ounce bottle of STA-BIL treats up to 80 gallons and costs $10 to $14 — cheap insurance against a $150 carburetor repair.
Frequently asked questions
- Why should I never use a regular bolt instead of a shear pin?
- Shear pins are designed to break under a specific load to protect the gearbox. A regular hardened bolt will not break. If the auger hits a rock or frozen obstacle, the force transfers directly to the gearbox, which can strip gears or crack the housing. Gearbox replacement costs $150 to $400. Shear pins cost $2 each.
- How often should I change snow blower oil?
- Once a year before the snow season is sufficient for most homeowners. If you use the snow blower heavily (more than 50 hours per season), change the oil mid-season as well. Always use the viscosity your manual recommends — cold-weather equipment typically needs 5W-30 for reliable flow at low temperatures.
- Why does my snow blower clog in wet snow?
- Wet, heavy snow sticks to the inside of the chute and auger housing. Spraying the chute interior and auger housing with silicone lubricant or a non-stick cooking spray before each use reduces clogging significantly. Never clear a clog with your hand — use the clean-out tool that came with the machine or a wooden broom handle.
- Should I run the snow blower dry at the end of the season?
- Add fuel stabilizer and run the engine for 10 minutes instead. Running the tank dry leaves residual fuel in the carburetor bowl that will still degrade. Stabilized fuel protects the entire fuel system through the off-season. If the fuel is already old, drain it, add fresh gas with stabilizer, and run the engine.
Products you'll need
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Snow Blower Maintenance Kit (check model)
Oil and filter kit — model-specific
STA-BIL Fuel Stabilizer (32oz)
Prevents fuel breakdown
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