Lawn Mower Blade Coming Loose..
- Thread starter Warstud
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Lock washer and use a self locking nut.
Originally Posted By: Warstud
Sharpened the blade a few weeks back. Since then the nut that holds the blade becomes loose and gets noisy after 10 minutes of use. What's causing this?
1) You under-torqued the nut/bolt when replacing the blade, and/or
2) you un-balanced the blade when sharpening it.
Sharpened the blade a few weeks back. Since then the nut that holds the blade becomes loose and gets noisy after 10 minutes of use. What's causing this?
1) You under-torqued the nut/bolt when replacing the blade, and/or
2) you un-balanced the blade when sharpening it.
Balance it very well and it'll usually never come off. You can use LocTite too (blue, not red), but its imperative you get it balanced well.
I usually sit mine on the side of a pencil to make sure its fairly accurate. Works well, never needed threadlocker that way yet.
I usually sit mine on the side of a pencil to make sure its fairly accurate. Works well, never needed threadlocker that way yet.
Originally Posted By: tommygunn
Balance it very well and it'll usually never come off. You can use LocTite too (blue, not red), but its imperative you get it balanced well.
I usually sit mine on the side of a pencil to make sure its fairly accurate. Works well, never needed threadlocker that way yet.
Use the LocTite Red. Don't be scared. Don't fool around with the blue. You will be able to get it back off, with the red.
Balance it very well and it'll usually never come off. You can use LocTite too (blue, not red), but its imperative you get it balanced well.
I usually sit mine on the side of a pencil to make sure its fairly accurate. Works well, never needed threadlocker that way yet.
Use the LocTite Red. Don't be scared. Don't fool around with the blue. You will be able to get it back off, with the red.
Originally Posted By: Chevys_n_Hawgs
Use the LocTite Red. Don't be scared. Don't fool around with the blue. You will be able to get it back off, with the red.
Actually it takes about 400F to break red loctite. I always use blue thread locker. Holds very well and does not require heat to break loose.
Use the LocTite Red. Don't be scared. Don't fool around with the blue. You will be able to get it back off, with the red.
Actually it takes about 400F to break red loctite. I always use blue thread locker. Holds very well and does not require heat to break loose.
Originally Posted By: tig1
Actually it takes about 400F to break red loctite. I always use blue thread locker. Holds very well and does not require heat to break loose.
Phooey!
Actually it takes about 400F to break red loctite. I always use blue thread locker. Holds very well and does not require heat to break loose.
Phooey!
If you're doing it correctly you'll never need something like Loctite to keep the blades on a mower. If you're incapable of getting it right, then you may need the extra crutch.
I sharpen mine every single week, and rotate between two sets of blades. I've never once used Loctite in hundreds of blade changes.
Originally Posted By: Warstud
Sharpened the blade a few weeks back. Since then the nut that holds the blade becomes loose and gets noisy after 10 minutes of use.
You have one of four things going on.
The blade is unbalanced. It has to be very unbalanced for it to work loose, but it's possible. Unless you took a huge amount off of one side for a rock chip, I doubt this is your problem.
You're not getting it tight enough. Make sure you get it breaker-bar tight.
You're missing a spacer or it's getting tightened off-center. Some blades require they be set onto a collar on the spindle, and they need to be snugged up just right before you really tighten them. If it's off center and riding on the high edge of the spindle rather than down on the base, it might seem tight, but will work loose in a few minutes. My old John Deere 325 was very picky about getting the blades on just right, and more than once I had to back a bolt out and recenter the blade on the spindle.
You're putting the blade back on upside down. If they're upside down they can work loose pretty quick.
I sharpen mine every single week, and rotate between two sets of blades. I've never once used Loctite in hundreds of blade changes.
Originally Posted By: Warstud
Sharpened the blade a few weeks back. Since then the nut that holds the blade becomes loose and gets noisy after 10 minutes of use.
You have one of four things going on.
The blade is unbalanced. It has to be very unbalanced for it to work loose, but it's possible. Unless you took a huge amount off of one side for a rock chip, I doubt this is your problem.
You're not getting it tight enough. Make sure you get it breaker-bar tight.
You're missing a spacer or it's getting tightened off-center. Some blades require they be set onto a collar on the spindle, and they need to be snugged up just right before you really tighten them. If it's off center and riding on the high edge of the spindle rather than down on the base, it might seem tight, but will work loose in a few minutes. My old John Deere 325 was very picky about getting the blades on just right, and more than once I had to back a bolt out and recenter the blade on the spindle.
You're putting the blade back on upside down. If they're upside down they can work loose pretty quick.
You mean that some lawn mower blades don't have a funny shape of them to prevent this???
You don't need to use locktight on the blade bolt. Something else is wrong.
A missing key in the crankshaft or broken/sheared key in the blade adapter will cause this.
When you took the blade off did the blade adapter fall off? If so, the key could have also fallen off and you didn't put it back. If the key is built into (part of) the blade adapter, is it intact or is it sheared?
Some blade adapters have a couple of nubs on them that correspond to holes in the blade, are the nubs sheared off?
A missing key in the crankshaft or broken/sheared key in the blade adapter will cause this.
When you took the blade off did the blade adapter fall off? If so, the key could have also fallen off and you didn't put it back. If the key is built into (part of) the blade adapter, is it intact or is it sheared?
Some blade adapters have a couple of nubs on them that correspond to holes in the blade, are the nubs sheared off?
Vibration has to be your problem. I actually put grease or anti-seeze on the bolts that hold by blades on, never had one come loose and I don't use lock washers either.
I'd say make sure they are balanced and use a lock washer for starters, anything other than that means you have bigger issues.
I'd say make sure they are balanced and use a lock washer for starters, anything other than that means you have bigger issues.
RE: You mean that some lawn mower blades don't have a funny shape of them to prevent this???
It's surprising how many blades with star patterns I take off riders and find the owner didn't get the concept of "fit the star shape around the star shape". Maybe not that surprising.
It's surprising how many blades with star patterns I take off riders and find the owner didn't get the concept of "fit the star shape around the star shape". Maybe not that surprising.
Impact wrench to tighten.
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