You’ve noticed that the blades on your riding mower aren’t cutting all that well and decide it’s time to remove them to sharpen them up. You’ve been through this process dozens of times before. You block the blade with a piece of 2×4 and a clamp and set to work on removing the bolt. But you run into a problem you’ve not experienced below. The spindle turns when attempting to remove the blade. So the bolt itself just spins and spins; there’s no resistance. How are you going to get it off?!
While a lawn mower blade bolt that’s stuck is not too uncommon, the issue of the spindle turning when removing mower blades is less common. I have got a few ideas you can try to fix this issue though.
How to Fix a Spindle that Turns When Removing Blades
This problem shouldn’t be confused with that of a lawn mower blade bolt that is stuck and won’t budge whatever you seem to do. That’s another problem. With this issue, we need to stop the spindle from spinning so you can get enough torque on the blade bolt to remove it.
Here are a few ideas on how you might do that.
Use a Wide Grip Wrench on the Spindle
It’s clear that you need to secure the spindle in some way so that it is not able to spin. The most obvious way to do that is by using a wrench and clamping it in some way.
You’re going to want to remove the pulley from the spindle first though. Trying to clamp the pulley is definitely not a good idea, as you’ll almost certainly end up damaging it, and then you’ll have a whole other problem to try and resolve. If the pulley does turn out to be stubborn, I wrote this post specifically on how to remove a stuck lawn mower pulley. Give the tips in that a try before you give up.
Once the pulley is out of the way and safely put to the side, clamp the spindle with the wide grip wrench. Make sure it’s locked on there tight, as you don’t want it slipping. If you have a smaller deck, you may not need to do anything else, as the sides of the deck will lock the wrench in place. If you’ve got a bigger deck, however, you may need to add an additional clamp onto the side of the deck to lock the wrench up against it.
This should prevent the spindle from turning when removing your blade. If you’re having trouble budging the bolt with a regular socket wrench, try using an impact wrench instead. The extra torque they can add will usually loosen even the most stubborn of bolts.
Engage the Clutch to Provide Resistance
This tip is only worth reading if you have a manual clutch as opposed to an electric clutch. If yours is electric, skip this one.
For this you are going to want to have your mower shut off. You’re then going to want to engage the clutch. In theory, this should prevent the pulley and spindle from moving as the main engine drive pulley won’t spin. At the very least it should provide some extra resistance and if you use a good impact wrench on the blade side, it might just do the trick.
Grind the Head of the Bolt Off
I should preface this by saying that I’ve never done this myself. I’m actually a little bit scared of doing so. The paranoid part of me thinks I’ll take too much off and then I won’t be able to get the body of the screw out.
But this is what I’ve seen a lot of folks recommending you do if you have a mower whereby the spindle turns when removing blades. You need to carefully grind the head of the bolt off and then leave it to cool down. You’ll still have the thickness of the blade and washer poking out of the threaded hole, which is enough for you to grab hold of and turn. You could use a pair of pliers too (I always find this stuff easier with pliers…damn small hands that I have!).
Final Thoughts
There you have it. A spindle that turns when removing blades can be a real head-scratcher at first, but it’s not a lost cause. You have options, namely:
- Locking the spindle up with some sort of wide grip wrench
- Engaging the clutch to provide the necessary resistance
- Grinding the head off of the bolt
Once you manage to get the bolt off, I’d also check out the condition of the spindle bearing. It may be worn and need replacing.
My nut on the blade turns but doesn’t come off. I think the spindle may be turning also. Suggestions?
Hi Ben,
If you have a vertical drive shaft connected directly to the engine, then you can take a look at the top of the engine. If the flywheel is turning, then when you turn the bolt it is still tight. If you have a bolt connecting the blade to a pulley, then take a look at the top of the pulley. If the pulley is spinning as you try to loosen the bolt, then again the bolt is tight and your attempt at loosening the bolt isn’t working.
The best way to get the bolt out is to lock the blade so it can’t move, then attempt to loosen the bolt. If this fails, you might need to put a wrench on the top of the pulley/flywheel to stop the spindle/driveshaft from spinning.
Good luck 🙂
Tom.