getting the blades off

[jima1]

My wife surprised me at Christmas with some beginner air tools /w3tcompact/icons/smile.gif, it's the <A target="_blank" HREF=http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=33567> Central Pneumatic set from Harbor Freight </A>

The first useful thing I thought to try it on is taking the blades off my KK 5' rear mower. The deck is at least 10 yrs old, I just bought it used a little over a year ago, this is my first attempt to get the blades off for sharpening. Cannot budge the bolts with 15" breaker bar, so I was hoping the impact wrench would make this job easy, even though it is low end. However, it just hammers real good, won't break loose. /w3tcompact/icons/frown.gif I'd appreciate some suggestions on what to try next.... /w3tcompact/icons/hmm.gif is this wrench too lightweight for the job?

Again, I'm a total beginner with air tools, and I've never had this mower apart either, probably there is something I'm doing wrong. My old Worthington compressor is small but it seems to hold 90 PSI ok. I did make sure the wrench was going in the reverse (loosening) direction...

Thanks,
Jim

 

[JohnMiller3]

<font color=blue>...Cannot budge the bolts with 15" breaker bar,...</font color=blue>

I'm assuming you're using a 3/4" socket set... use a 3-4' pipe on your breaker bar as the extension... and the laws of leverage works in your favor... /w3tcompact/icons/smile.gif

On my KK... I believe they were torqued over 500 ft. lbs. on the blade bolts... short of using a super 3/4 or 1" drive air impact wrench... I've never seen anyone's 1/2" impact wrench take those nuts off... /w3tcompact/icons/blush.gif

 

[usedcarz]

if you have access to a torch, put a LITTLE heat on the nut and then spin it off. i had same problem on my kubota and on the king kutter mower also. i took them into my shop which compressor carries 180 psi versus mylittle unit at home. the big ole psi made the difference real quick, zipped them both right off. but the heat will work. just don't want to get hot enough to damage any seals or bearings in the hub units. even a little propane plumber's torch would get it hot enough to make a difference.

 

[normde2001]

That would require a bigger impact wrench. Your is 230ft/lbs max and those bolts are probably 500-600ft/lbs or more plus corrosion. I would soak them in "PB Blaster" and find about a 3' pipe to fit over your breaker bar. An impact wrench big enough to handle that job would cost $200-$300.

 

[jima1]

Thanks for the suggestions guys, I guess my new toy is not up to the task....I'll go shopping for some heat, PB blaster, and pipe, they've got to be a lot less than the big impact wrenches, I don't have enough uses to justify that.

Jim

 

[rdbrumfield]

Heat is the best answer, at least that has been my experience. Melt some bees wax on them if you have any, you will be amazed.

 

[em14]

I have never heard of melting Bees Wax on a rusted nut and bolt to help loosen them ... what does this do? This is a new one on me ... Does the wax melt and then penetrate the rust?
Leo

 

[Anonymous Poster]

Please don't take this wrong..! Are they left hand threads, my woods was. George

 

[Bird]

Jim, that's a nice little set of wrenches for a lot of jobs, and I've owned and used quite a number of Central Pneumatic tools myself. However, compare the 230 ft./lbs of torque the cheap impact wrenches produce to the 425 ft./lbs. of an Ingersoll-Rand IR231 (quite possibly the most popular impact wrench in the country) and the Chicago Pneumatic CP734. The IR2131 even tightens to 450 and will break loose up to 600. Those are all 1/2" air impact wrenches that use 90 psi air pressure but the performance varies greatly, and of course, the price increases with the performance. I never found a mower blade that my IR231 wouldn't take off, but if I were going to do a lot of work with an impact wrench, I think I'd have to spring for an IR2131.

 

[JimMc]

Just as an indication of what you're up against, during production of our cutters we use a 1" drive impact for assembly of the blade bolts, and then follow that up with a torque multiplier/torque wrench. Our line pressure at the gun is regulated down to 120PSI and our tank pressure runs about 180. Of course, we don't just keep hammering with the impact gun, that would over torque the bolt, but it's still more than the average 1/2" drive gun will remove.