Removing Mower Blades

[rickmacheske]

Does anyone have a good way to remove the bolt on mower blades? My 6' mower needs the blades sharpened but I can't get the blades off. I've tried WD-40, putting a torch on the bolts, hitting them with a hammer, nothing seems to break them free. Any hints?
Thanks,
Rick

 

[Bird]

Rick, naturally my preferred method is a pneumatic impact wrench, which I'll assume you don't have. If you have an air-compressor, then I'd buy an impact wrench (be sure to check the specs on any of them to see how much torque they're rated for because cheap ones work just fine, but some do not have enough power). And of course if you don't have an air-compressor . . ., well, I don't know how anyone does without an air-compressor. /forums/images/graemlins/laugh.gif

 

[milkman]

Nothing in your profile and you don't mention what make mower, so it's hard to help, some mowers have left hand thread bolts holding the blades. Possibly the problem? /forums/images/graemlins/confused.gif

 

[3RRL]

Rick,
Assuming that's a brushhog type mower, a lot of guys just tilt them up and use an angle grinder to sharpen.

 

[rickmacheske]

Thanks guys. I had a fairly cheap impact wrench. I had tried that before posting. I went out and bought a "professional" version. With that and solvent, the bolts spun off in seconds. Having good tools sure helps.
Rick

 

[john_bud]

Rick,

That is an excellent illustration on the difference between a $29.99 impact wrench and a real one! When it comes to air tools, spend the money and buy the good stuff!

jb

 

[EddieWalker]

Be sure to know what you need to torque them down to when putting them back on. My Landpride blades are to be at 500 pounds.

Eddie

 

[Pks]

<font color="red"> My Landpride blades are to be at 500 pounds. </font>

Be careful with the units on those blades! By definition Torgue comes with two units: force and distance. So 500 pounds over what distance: Inches or Feet? 500 inch pounds is about 41.7 foot pounds.

 

[EddieWalker]

Sorry if you thought I meant inch pounds. My mower blades are to be torqued down to 500 foot pounds!!

Eddie

 

[Bird]

Eddie, actually I do believe in having nuts and bolts torqued to manufacturers' specs; however, I don't always do it. /forums/images/graemlins/wink.gif I think 500 is also what my Howse brush hog said to torque them to, and the first time I dropped the entire blade and stump jumper assembly, I found that I didn't have a socket of the right size to remove the blades, and didn't even have an open end/box end wrench of that size. So I got out my 10", made in Taiwan, genuine Crescent imitation, adjustable wrench and was wondering whether I'd break it if I put in on there and hit it with my 4# hammer. I was really surprised when I found that I could quite easily unscrew those nuts with the 10" wrench, one hand, and no hammer needed. Just didn't know my own strength, I guess. /forums/images/graemlins/grin.gif Anyway, I bought the right socket for my half inch 425 ft. lb. impact wrench to put them back on and figured that was close enough. /forums/images/graemlins/wink.gif

 

[Highbeam]

I thought for sure my big honkin sockets would be big enough but I looked and they aren't. I can't get my adjustable wrench on it to measure but my eyeball gives me 1-5/8". What is the size of a brush hog blade nut? I am thinking 1.5" sounds familiar.

 

[EddieWalker]

Highbeam,

When I first did mine, I had to call LandPride and ask a tech for the size of the nut. Mine is a 1 11/16's inch. All there stuff in in Standard sizes.

I had to pay $40 for that socket and I got lucky on Ebay and found a Proter Cable impact wrench that will do 500 foot pounds for $80.

I just tighten it as tight as the impact will get them and figure that's close enough.

It's allot of money for the socket. I've used the impact quite a bit, but that socket has only been used a few times.

Eddie

 

[Bird]

Joe, like Eddie, I had to buy a high priced socket that I used for nothing else. And I had to do it twice! I bought the one to fit my 4' Bush Hog, then later when I got the 5' Howse, it was a different size so I had to buy another one. /forums/images/graemlins/frown.gif

 

[Highbeam]

Oh cripes, I'll have to call the manufacturer. I can buy a set of HF 3/4" impact sockets for not much more. But I will need to know the size. I bent something, either a blade or the stumpjumper so that one blade tip swings a good 1.5" higher than the other. I'm hoping it is the blade so I can heat and pound.

 

[Highbeam]

So after searching it seems 1-11/16" is the most universal nut size out there for the 4-6' decks and from howse to woods.

 

[Kyle_in_Tex]

My dealer sells a "kit" which is a 3/4" drive 24"long breakover bar with a big socket. You'll need to put an extension pipe over the breakover bar. I would use another 3 foot of extension to more easily loosen/tighten the nut. Eddie's right, they need around 500 ft/lbs.

 

[EddieWalker]

</font><font color="blue" class="small">( I bent something, either a blade or the stumpjumper so that one blade tip swings a good 1.5" higher than the other. I'm hoping it is the blade so I can heat and pound. )</font>

Highbeam,

If you heat and bend your blade, you might have strength problems with it. But even more of an issue is wether or not you'll through them out of ballance. I bent one also and found it to be easier to just put new ones on.

The first time it's a pain, but I've done it twice now and it was real easy the second time around.

If it was the stump jumper, I'm clueless on that one. /forums/images/graemlins/confused.gif

Eddie

 

[JustGary]

I've found that my cheap impact wrench impacts much better if I oil it right before the job. Even your new "pro" one would like that. You didn't mention it, so I thought I'd toss it out for everyone. Glad to hear you got it done.

- Just Gary

 

[Highbeam]

I'm having trouble sourcing the 1-11/16 socket. Not at NAPA and not included in the sets of big sockets. I guess I'll try a Sears next.

I did discover that the stumpjumper retainer nut had loosened. The big ol' nut with a cotter needed to be tightened a good 1/4 turn which leveled out the blades somewhat. Is there a woodruff key or something similar on the drive spindle to keep the stumpjumper keyed to that shaft? I am gimped up right now so did not want to take the nut off and see what caused it to loosen.

I have had pretty good luck heating things up with a weed burner or rosebud and beating them with the sledge to get them straight. I then let them cool slowly t otry and prevent them from becoming brittle. If it is bent and the repair makes them break then so be it.

 

[EddieWalker]

I doubt you'll find anything large at Sears. I didn't, but maybe you have a better store than I do. LOL

Mine is a Proto and I definiately paid for the name on it!!!

I'd call around first, it's not an easy size to find. Only one place in my town had them.

Eddie