Cannot Remove Blade Bolt

I have a seven year old Toro 22" Recycler front-drive walk behind mower model no. 20016. Last week I tried to remove the blade to replace it and the bolt would not budge. I blocked the blade with a length of 4x4 to keep it from moving but the crankshaft turned instead. The last time I sharpened the blade, less than two months ago, I torqued it to 60 ft/lbs. I have a two-foot long 1/2" drive breaker bar that I can try on it, by jerking it, but I'm worried I will just wring off the head of the bolt. How strong are the blade bolts?
The only way I see to get to the shaft to stop it from turning is from the top by blocking the starter cup or the flywheel. Anyone else had this problem and have a solution?
I'm still mowing with the old blade, but I need to replace it soon.

 

You need to use an impact wrench.
The repeated short blows will have it off in no time.

 

Dang, I hadn't thought of that. Great idea, thanks GregH.

 

An impact wrench is a gr8 idea for a Stubborn blade bolt
but If the head of the bolt is stripped and all else fails take a hand held disk grinder and grind the flat and lock washers out from under the blade bolt. This relives pressure from bolt. And it will come out EZ.Don’t forget to were eye protection.

 

Aarrgh! I haven't been able to remove that darn bolt yet, even with an impact wrench. It just won't budge. I came to ask if heating the bolt with a torch would help, but I think I will try repair_guy's suggestion first. I don't have a disk grinder, but my BIL does. There is only one lock washer under the head; I might have to buy a thinner blade for it.

 

Don't let it get to ya roy overthehill,I got into small engine repair B 4 impact wrenches come out.what I have learned is 'there's more than one way of getting a job done'.It might take a little longer but the end results is the same.Heating the bolt will just swell the bolt in the shaft.Then you will be in trouble.And heating the shaft will take the temper out and make it weaker.Best bet is probally is to grind a slot 90 ' from slot in lock washer,and then beat the wesher off with a hammer and chesel.Then un-screw bolt with vise grip plairs.

Good luck

 

Thanks, repair_guy. That's one of the things I was wondering about if I heated up the bolt, so I won't do that.
After my first try with my impact wrench, I noticed the 12 pt. socket was starting to damage the bolt head so I bought a 6 pt. impact socket and thought 'now I'll get that sucker off quick.' WRONG! I even removed the plastic cover and starter rope recoil unit so I could back-up the crankshaft with a length of 2x2 between the starter cup and a nearby tree. That didn't help either.
I plan to call my BIL today and see about that grinder. Thanks.

 

overthehill;
Before you break something, to lock the engine, turn the engine until it is on the compression stroke, remove the sparkplug and fill the cylinder with a small rope, like pull start rope, leave a little hanging out, now when you try to turn the engine the engine will try to compress the rope and stop and nothing will get broken, when finished, back the engine off a little and remove the rope. Have a good one. Geo

 

That's a good idea, geogrubb, but I'm thru banging on it. I'm gonna grind and chisel that washer outta there to relieve the pressure. Thanks.

 

Roy,, Sorry to sound silly here,, but are you sure you're turning it the right way??? It shouldn't be this tight as you say you torqued it two months ago... It will turn ""Counterclockwise"" when looking @ it from the BOTTOM of the mower...(not the top) I know it's easy to confuse the left & right when your looking @ something upside down & on your back & the dog thinks you want to play,,, Anyway,,, hope this helped... Roger

 

Success! I finally removed that darn bolt yesterday. I ground down the lock washer some, then chiseled it out the rest of the way and didn't damage the bolt. I figured I'd have to put a wrench on it to back it out, but it turned easily by hand with the washer gone. That lock washer sure lived up to its name.
Thanks all, especially repair_guy for the good advice.