If you've spent any time clearing deep drifts in the driveway, you might be considering a john deere 47 snowblower gearbox upgrade to keep your machine from giving up the ghost mid-storm. It's one of those projects that sounds intimidating when you first look at the parts diagram, but once you get into the guts of the blower, it starts to make a lot of sense. The 47-inch snowblower is a legendary piece of equipment, but as many owners know, that central gearbox can be a bit of a weak link if you're pushing it through heavy, wet slush or ice-crusted banks.
Why the Stock Gearbox Struggles
The thing about the standard setup on the John Deere 47 is that it was designed to be a "fail-safe" system. Usually, there's a shear bolt meant to snap before any real damage happens to the internal gears. However, physics doesn't always play nice. Sometimes that shear bolt holds on just a little too long, or the internal brass gear simply gets tired after ten or fifteen years of service. When that happens, you'll hear a nasty grinding noise, and suddenly the augers won't turn even though the PTO is spinning like crazy.
Most guys looking into an upgrade are tired of the "soft" feel of the factory internals. The original worm gear is often made of a softer bronze or brass alloy. While that's great for reducing friction, it's not exactly a lifetime part. Over time, the teeth wear down until they're as thin as paper. A proper john deere 47 snowblower gearbox upgrade usually involves moving to a heavy-duty gear set or, in some cases, swapping out the entire housing for something more robust if the old one has been cracked or wallowed out.
Getting the Right Parts for the Job
Before you go tearing everything apart in your garage, you need to know what you're actually looking for. There are a few different versions of the 47 blower out there—some have the older cast iron housings, while others have the newer aluminum ones. Most folks doing the john deere 47 snowblower gearbox upgrade are looking for high-quality replacement gears that can handle more torque.
You'll find a lot of debate on the forums about whether to stick with OEM (Original Equipment Manufacturer) parts or go with an aftermarket kit. Honestly, some of the aftermarket kits these days are actually beefier than what came from the factory back in the 90s or early 2000s. You want to look for a gear set that uses a high-tensile strength alloy. Some enthusiasts even look for specialized kits that include better seals and bearings, because if you're going to open the case anyway, you might as well replace the parts that keep the oil in and the water out.
The Importance of Good Bearings
While everyone focuses on the gears, the bearings are the unsung heroes of the john deere 47 snowblower gearbox upgrade. If your bearings have any play in them, your new gears aren't going to mesh correctly. This is how most people ruin their new parts within the first season. When you're shopping for your upgrade kit, make sure it includes (or you separately buy) high-quality Timken or similar grade bearings. It makes a world of difference in how quiet the blower runs.
Seals and Gaskets
Don't even think about reusing the old seals. Once you break that factory seal, it's done. A big part of the upgrade process is ensuring that the gearbox is airtight—well, as airtight as a piece of farm equipment can be. Moisture is the enemy here. When snow melts and seeps into the gearbox, it turns your gear oil into a milky mess that doesn't lubricate anything.
The Process: What to Expect
Let's be real for a second: this isn't a thirty-minute job. Doing a john deere 47 snowblower gearbox upgrade involves taking a good chunk of the blower apart. You'll have to pull the augers, which usually involves fighting with some rusted-on shear bolts or stubborn woodruff keys. If you haven't had your augers off in a few years, get the PB Blaster or your favorite penetrating oil ready a few days in advance.
Once you get the gearbox out of the frame and on your workbench, the real fun begins. Opening the case is usually pretty straightforward—just a few bolts—but be prepared for the smell. Old gear oil that's been chewed up by failing brass gears has a very specific, unpleasant aroma. Clean everything out with some brake cleaner so you can actually see what you're working with.
Checking the Shafts
While you have the gearbox open, take a close look at the input and output shafts. If there's scoring where the seals sit, you might need to do a bit of light sanding with emery cloth, or in extreme cases, replace the shaft entirely. A john deere 47 snowblower gearbox upgrade won't do much good if the shaft is wobbling around like a loose tooth.
Shimming for Success
This is the part where people usually get frustrated. To get the gears to last, you have to shim them correctly. If they're too tight, they'll overheat and bind. If they're too loose, you'll strip them out again in no time. Most upgrade kits come with a variety of thin shims. You want just a tiny bit of backlash—not much, just enough so the gears aren't jammed against each other. It's a bit of a "feel" thing, and you might find yourself taking the case apart and putting it back together three or four times before it's perfect.
Choosing the Right Lubricant
After you've finished the john deere 47 snowblower gearbox upgrade, you can't just throw any old grease in there and call it a day. Most of these gearboxes require a specific type of gear oil—often a 75W-90 or an 80W-90 synthetic. Some guys swear by using "corn head grease" (a John Deere specialty), which is a thixotropic grease that acts like a liquid when the gears are moving but turns into a gel when they stop. This is great for older gearboxes that might have slight leaks because it won't just run out onto your floor. Check your manual or the instructions that came with your upgrade kit to be sure.
Prevention and Maintenance Post-Upgrade
Once you've got everything back together and the blower is humming along quietly, you want to make sure you don't have to do this again for another decade. The biggest thing? Check your shear bolts. Make sure you're using the correct grade bolts. If you use a Grade 8 bolt because you're tired of them snapping, you're basically asking for the gearbox to fail instead. The bolt is supposed to be the "fuse" in the system. Let it snap! It's way cheaper and easier to replace a two-dollar bolt than it is to do another john deere 47 snowblower gearbox upgrade.
Also, get into the habit of checking the gear oil level at the start of every season. It only takes a minute, but it can save you a massive headache. If the oil looks milky, change it immediately. That means water got in, and water is the fastest way to kill your new gears.
Is It Worth the Effort?
You might be wondering if it's better to just buy a new blower or find a used one. But if you've got a solid tractor and a frame that isn't rusted through, the john deere 47 snowblower gearbox upgrade is absolutely worth it. These 47-inch blowers are built like tanks compared to the stuff you find at big-box stores today. Taking a Saturday to rebuild the heart of the machine ensures that when the next "Storm of the Century" hits, you'll be the one actually getting the job done instead of standing in the garage staring at a pile of broken parts.
In the end, it's all about peace of mind. There's a certain satisfaction that comes from hearing that low hum of a freshly rebuilt gearbox as it effortlessly throws snow twenty feet into the air. It turns a chore into something that's actually kind of fun. Plus, you'll know your machine inside and out, which is always a bonus when you're the neighborhood guy everyone calls when their driveway is buried.