Snowblower gearbox grease is a vital component to the health of a snowblower. This thick goo protects the gears located in the gearbox. The gearbox is where power is transferred from the impeller housing to the auger shaft. If you neglect it, be prepared for a costly repair.
Tools Needed (Commissions Earned)
A gearbox is found on a two stage snowblower. It’s in the front of the machine in the auger housing. It’s the little box that connects the impeller shaft to the auger shaft.
Since the impeller shaft is driven by the engine, the power needs to convert 90 degrees to the augers. By using the gears found within the box (hence the name), the power is efficiently converted.
That is, along as the gearbox is adequately lubricated.
Like anything else that is related to machinery, friction is the enemy of metal components. Without the proper lubrication, parts will wear prematurely and cause excessive damage.
You might not think it, but those little gears found in the gearbox are surprisingly expensive, so it pays to keep them in good shape.
How to Change Snowblower Gearbox Grease
All grease will dissolve over time. It will begin to separate and get runny. The oil will begin to seep past the gearbox seals, and that’s a good indication that it’s time to replace the grease.
While you’re at it, we’re going to have to disassemble the gearbox, so you may as well replace the seals. They’re cheap enough, and you don’t want to have to tear back into the gearbox before you need to.
If You’re Only Filling and Not Replacing
This depends on your machine and the recommended lubricant. Some manufacturers recommend a thick grease paste in the gearbox. To refill or replace this kind of grease, you need to separate the gearbox so the instructions are more or less the same for replacing.
However, I like to use a somewhat more liquid form of gear oil, like a 90w. If you have a fill port on the gearbox, then it’s as simple as filling it up. It all depends on the type of machine that you have.
That being said, if it’s gotten to the point where the gear oil is seeping past the seals, then you’re better off splitting it apart and cleaning the old gunk out.
Removing the Gearbox
It’s not as bad as it sounds, really.
First, we need to split the auger housing from the engine. This is easy enough; it’s usually two bolts, one on each side.
With those off, then the auger belt can be slipped off the pulley and we can pull the auger housing apart from the engine and drive train.
Now we need to remove the pulley from the rear of the impeller shaft. This is just bolted on, and it can help to have an impact driver to remove it.
With the pulley off, all that’s left is the few bolts on both of the sides of the auger housing. Usually there’s three on each side.
With those out, the whole auger and impeller system will come out as one unit.
Splitting the Gearbox
Now that the whole system is out, it’s as simple as removing the few bolts found on the gearbox body. While this can technically be done while in the machine, it’s far easier to remove it all. Plus, you can do a better job of cleaning.
So even though it seems like an extra hassle, you’ll save time in the end.
Once the bolts of the gearbox body are removed, the gearbox should split apart. It might need a little persuasion.
Take note that the seals are seated in the two halves of the gearbox. There should be three of them; one for the impeller shaft and one for each of the auger shafts.
Be sure to clean the shafts well to ensure a good fit with the new seals. Take note of how the gears are aligned within the box, and remove them all one by one.
Clean the Gearbox
With everything out, clean it all thoroughly. You can use some brake cleaner or carb cleaner, or any other spirit that you have handy. Scoop out as much as you can prior to hosing it down.
While everything is out and getting cleaned, inspect all of the gears for any wear. This would be a good time to replace anything that you need to (especially seals) while you have it all apart.
Refill the Gearbox
With everything cleaned, I like to assemble half the gearbox and load that half with grease. Then do the same with the other half. Then, start meshing the two halves together. You have to move the augers around a bit for the gears to align.
Before you get everything seated, try to cram some more grease in there. Essentially when it comes to grease, there’s no such thing as too much; but there certainly is too little. Anything extra that can’t physically fit in the gearbox will get squeezed out, and you can just clean that up.
With the gearbox refilled, go ahead and repeat the steps in reverse to reinstall everything.
Recap
Since I pick up a lot of old snowblowers to repair and flip, I’m used to changing gearbox grease. While this isn’t a super common repair for the average homeowner, it’s important that you know how in order to prevent costly damages. Just keep an eye out for oil leaking from the gearbox – that’s your clue that it’s due for replacing.
Did I forget anything? Let me know in the comments below!
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