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I want to remove my blade to sharpen it but the spindle just turns.
How can I keep the spindle from turning?

Dhamilton said:

I want to remove my blade to sharpen it but the spindle just turns.
How can I keep the spindle from turning?

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Use a short 2x4 to block the blade.

Yeah, block of wood if you don't have an impact wrench.

Reviving an old thread. I have the same problem. I blocked the blade with a wooden block but when I try to break the nut loose, the spindle turns along with the pulley above the deck... I've sprayed with PB blaster, waiting for it to hopefully break the rust while I am writing this. I see no flat side on the spindle so that I could hold it in place with a wrench and stop it from spinning (as some circular saws have). The spindle has another nut at the opposite end (on top, on the other side of the deck) so I could use a wrench on that but there is a chance that the top nut (holding the pulley) will break loose instead of the blade side nut.

It is a Murray Select riding mower with a 42" deck (16.5HP). I bought it used and I don't have the manual for it. I would love to check if the nuts are fastened clockwise or counter clockwise but the tag under the seat is so faded that I can't make out the model number.

Does anyone have this information?
Any input is appreciated. Thank you!

Use a nut splitter and buy a new nut
If the blade is a riht hans cut then the blade will have a right hans nut so it self tightens in use, rather than self loosens in use
Then thread below the nut gets rusty & caked in dirt so start with doing it back up tight and cleaning the thread
The spindle pulls out from the bottom so you can pull it out with the blade still on then hold the spindle in a vice to attack the blade nut .

bertsmobile1 said:

Use a nut splitter and buy a new nut
If the blade is a riht hans cut then the blade will have a right hans nut so it self tightens in use, rather than self loosens in use
Then thread below the nut gets rusty & caked in dirt so start with doing it back up tight and cleaning the thread
The spindle pulls out from the bottom so you can pull it out with the blade still on then hold the spindle in a vice to attack the blade nut .

Click to expand...

Thanks for the suggestions, Bert. I left it drenched in PB Blaster overnight and it broke loose with an impact driver the next day. It saved me the trouble of splitting and replacing the nut. Also, if anyone else has this model, I can confirm it tightens clockwise (looking upward, from under it).

How will you prevent that too tight problem in the future?

By design that nut only needs about 40 ft. lbs of torque .

SeniorCitizen said:

How will you prevent that too tight problem in the future?

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You could use a drop of anti-seize but it is a risky place to do so, as the nut might loosen while mowing.

I just gave the thread a good clean with a wire brush and then brushed some engine oil onto it. Oil tends to soak into the pores and keep moisture out (thereby lowering the chance of rust and seize).

I tightened each nut well after cleaning and oiling the threads and switched blade types a couple of times after that, without any trouble whatsoever. I should add that I did use an impact driver every time, just because I was in a rush and it was handy. I feel plain oil hits the right balance between too little or too much lubrication for this application, just make sure the spindle/nut threads are as clean and dry as possible when you apply it, otherwise I don't think it will work as intended, as you may actually trap humidity in the pores.

Bolts said:

Thanks for the suggestions, Bert. I left it drenched in PB Blaster overnight and it broke loose with an impact driver the next day. It saved me the trouble of splitting and replacing the nut. Also, if anyone else has this model, I can confirm it tightens clockwise (looking upward, from under it).

Click to expand...

"Clockwise"
That's why they don't loosen with 40 lb. torque .

Any dope be it oil, anti-sneeze or what-have-you will lower your final torque value. So lubed up will require less torque.

use a block of wood to lock up the blade from turning. I wedge it against a bolt or bump out or lay the mower on its side and step on the board to hold it. Torque values are normally a range. Use the lower range if you cleaned and oiled the bolt, or the higher if it is dry. Most manufacturers will send a new oiled bolt if you order a part from them, so the factory is often using an oiled bolt on assembly. When I say oiled, I mean lightly glistening and not wet with oil.