Snow Blower Maintenance: Pre-Season Checklist and Schedule

A gas snow blower needs the same engine care as a lawn mower, plus the parts that take a beating from ice and packed snow: shear pins, belts, the scraper bar and the skid shoes. A shear pin, also called a shear bolt, is a soft bolt that holds the auger to its shaft and is designed to snap when the auger hits something solid, so the gearbox does not break instead.

Battery snow blowers have no oil, spark plug, carburetor or fuel, which removes most of the storage problems. They still have an auger, a scraper bar, a chute and, on two-stage models, an impeller that need inspection, and their batteries need correct charging and storage.

Most homeowners put 10 to 30 hours a season on a snow blower, so for many jobs the season comes before the hour count. Do whichever comes first.

Use the oil grade on the temperature chart in your manual. For most four-stroke snow blower engines that means a 5W-30, and many manufacturers recommend synthetic 5W-30 for the coldest starts, such as Briggs & Stratton 5W-30 synthetic. Straight SAE 30 is a warm-weather oil and makes cold starts harder. Never put 2-stroke oil in a 4-stroke engine.

To change it: run the engine outdoors for a few minutes so the oil flows, shut it off and let it cool enough to touch, then disconnect the spark plug wire. Drain into a pan through the drain plug or drain tube, replace the plug, and refill slowly to the full mark on the dipstick. Engine capacities are small, often well under a quart on 200 to 300cc engines, so overfilling is easy. Take used oil to an auto parts store or recycling center.

Inspect the plug every season and replace it at the interval your manual gives; many owners simply replace it every fall because a plug costs a few dollars and a hard start in the cold costs a morning. Use the exact plug your manual lists, from a replacement spark plug search by your engine model, and set the gap with a feeler gauge to the manual's figure.

A plug with black, sooty deposits points to a rich mixture or a dirty air intake; a wet, oily plug can mean overfilled oil or a machine tipped the wrong way. Remove the plug only with the engine cool, and thread the new one in by hand before snugging it with a plug socket so you do not cross-thread the aluminum head.

Shear pins break because they are supposed to. When a two-stage auger hits a frozen newspaper, a chunk of plow ice, a rock or a landscape edge, the soft pin snaps and the auger stops turning on its shaft while the engine keeps running. That sacrifice protects the auger gearbox, the shaft and the impeller, which cost far more to repair.

Never replace a shear pin with a hardware-store bolt. A standard grade 5 or grade 8 bolt is much harder than an OEM shear bolt and will not shear. The next time the auger hits something, the shock goes straight into the gearbox gears or bends the auger shaft instead, turning a $10 fix into a major repair, and some manufacturers note that non-OEM parts can affect warranty coverage. Buy the exact shear bolts for your machine, such as the Husqvarna Two-Stage Snow Blower Shear Bolt Kit, 6 Pack for Husqvarna and Poulan two-stage models ($9.49), and keep a few in a bag zip-tied to the handle.

To replace one: engine off, key out, spark plug wire disconnected, and wait for every part to stop. Line up the holes in the auger and shaft, tap out the broken halves, insert the new bolt and nut, and tighten to snug. If pins break often, look for the cause: debris on the driveway, a housing set too low on gravel, or feeding packed berm ice too fast.

The classic symptom is an engine that runs at full speed while the auger slows or stops as soon as it meets snow, or a drive that slips on a slope. A squeal, a burning-rubber smell or black dust inside the belt cover tells the same story. With the engine off and the spark plug wire disconnected, remove the belt cover and look for cracks across the belt, frayed edges, a shiny glazed surface or stretching that lets the belt ride low in the pulley.

Some slipping is only a cable out of adjustment, so check the auger control cable against the manual first. If the belt is worn, replace it with the part number from the manual; a generic belt with the wrong length or angle slips no matter how you adjust it. The auger belt usually wears first on machines that clear heavy plow berms.

The scraper bar is the replaceable steel or poly strip along the bottom of the auger housing. It takes all the wear from pavement, and when it wears through, the housing itself starts grinding. Many scraper bars are reversible, so flip it when one edge is worn, and replace it when both are.

Skid shoes are the adjustable runners on each side of a two-stage housing that set how high the scraper bar rides. Set them low for smooth concrete and asphalt, and higher for gravel, pavers, stamped concrete and uneven surfaces, at the heights your manual gives. Set both sides the same, on a flat floor, so the housing does not cut at an angle. Worn steel shoes can leave rust streaks on light concrete; composite shoes such as the Ariens Reversible Composite Skid Shoe Kit avoid that on Ariens machines.

On the auger itself, look for bent flights and cracked welds on two-stage machines, and worn rubber paddles on single-stage machines, which stop picking up snow cleanly once they wear past the line. Turn the auger by hand only with the engine off and the plug wire or battery removed.

Use the pressure range molded on the tire sidewall or listed in the manual, and set both tires to the same number. Pneumatic snow blower tires lose pressure in cold weather, and a machine with one soft tire pulls to that side and wears the scraper bar unevenly. Check them before the season and again after a hard cold snap.

If you fight flats every year, airless tires remove the chore; the EGO Power+ SNT2420 24 in. Two-Stage Snow Blower (Tool Only) uses 14-inch airless snow tires. Tracks, as on the Honda HSS928AATD 28 in. Two-Stage Track Snow Blower, have no pressure to check but should be inspected for cuts and correct tension.

Battery machines skip the engine work entirely, but four jobs remain:

• Batteries: bring them indoors after each use, let them warm to room temperature, then charge them per the manual. Store them indoors, never in an unheated garage for the off season, and at the charge level the manual recommends. Never charge or use a pack that is swollen, cracked, leaking or has been dropped hard; recycle it through a battery drop-off program.
• Auger and scraper: check the auger, paddles and scraper bar as you would on a gas machine. Two-stage battery models may use shear bolts; check your manual.
• Moisture: wipe snow off the machine and battery compartment after each use. IPX4 models such as the EGO Power+ SNT2122 21 in. Single-Stage Snow Blower Kit resist splashing, not submersion, and should not be hosed down.
• Chute and controls: keep the chute rotation smooth and free of ice.

If you run a large EGO two-stage, a second high-capacity pack such as the EGO Power+ BA5600T 56V 10.0Ah Battery lets one pack warm indoors while the other works. The battery snow blower buying guide covers watt-hours and cold-weather capacity.

End-of-season care decides whether the machine starts next winter. Change the oil so acidic combustion residue does not sit in the engine all summer, deal with the fuel exactly as your manual directs (stabilize it or run the fuel system dry), clean off salt and grime, touch up bare metal, and cover the machine. The full process, including cover picks and space planning, is in how to store a snow blower.

If this is the season your machine finally wore out, size the replacement to the driveway rather than repeating the old one: the best snow blowers roundup covers everything from 21-inch battery models to the Honda HSS928AATD 28 in. Two-Stage Track Snow Blower, and the Honda HSS928AATD review covers the buy-once option.