Rotary Cutter Removing Rotary Cutter Blades

[MarkOnTheRiver]

Over the past 9 months I have had my Bush Hog 285 I have run over numerous rocks, some as big as bowling balls. Well it's a new season and time to get the cutter into shape, not the least of which is the need to remove the blades so that I can pound them back into shape before sharpening.

Since this is the first time for me to try and take the blades off and the first time for the cutter as I bought it new, I'm looking for advice and the best way to do this. Will a 230 ft/lb impact wrench be enough to take the nut off (I suspect not)? If not, I guess I'll be needing:

1-11/16" socket
3/4" drive, 8" extension (those with a 285, will a 5" one be alright?)
3/4" Drive, 18" Flex Handle (breaker bar)
4' pipe to fit over Flex Handle for a little extra persuasion

And boy these items are expensive (a total of 106.97 at Sears).

Mark

 

[john_bud]

You forgot to get synaptic lubricant (beer) and work out for a while. IIRC, those bolts are spec'ed at 450 ft-lb tightened. If they have been on for a while and beat up, you will probably need a smoke wrench (ox/ac) or an abrasive cutting wheel. I've seen 3/4 inch impacts running 175 psi get laughed at by some of those bolts~!

Oh, you really can't pound them back into shape. They will be much more prone to breaking if you do. Either sharpen them in place or put in new.

Enjoy!
jb

 

[greg_g]

If you already bought those items - specifically to remove rotary cutter blade bolts - then I'd say the $106.97 would have been better spent on a good angle grinder. You can sharpen the blades right on the mower, and almost certainly have money left over.

//greg//

 

[bota7800]

I need to get my blades sharpened too.

I have the angle grinder so that sounds easier. But, is there the same need to balance the blades that there is for conventional mower blades? My guess is that it is not too critical (within reason, because of the flywheel effect of the center disk) Can you just sharpen each blade in place until they look even?


If I am off base feel free to set me straight.


thanks

 

[RalphVa]

I had no trouble getting the blades off my LX4 at all. It has an access hole through the deck once the tail wheel assembly is removed. One nut came off with my 550 ft-lb impact wrench. The other required a 6' pipe placed over the 3/4" drive wrench, but not that much force.

Sharpened using my bench grinder. Can't imagine trying to hold those things in place with an angle grinder. Some folks must have more hands to hold everything in place than I do.

Putting the blades, slump jumper and bolt back in place just required a couple quick clamps. All in all, it was an easier exercise than removing and replacing the 2 crossed blades on my Gravely brush hog.

Ralph

 

[Farmwithjunk]

I just bought a new Bush Hog 286 a few weeks back. I decided to get a second set of blades while I was at it. A pair of NEW blades (O.E.M. Bush Hog) were only $62, shipping included. I was astounded that they were that cheap. Dealer said the price was "a little below list", but even with that, I would just replace rather than "pound 'em back into shape".

 

[Gatorboy]

The impact wrench should work ... but it may take time, depending on how tight the nut is.

 

[gizmo]

I don't know how your's is set up, but my VERY old FMC cutter has jam nuts on the back side of the blade bolts. The blades came off a lot easier once I figured out that the nuts were there and got them loosened. By the way, I had to loosen the nut with a come-along attached to the end of a 2' by 1.5" box end wrench.

 

[Highbeam]

I don't worry much about balancing them after or during sharpening with the 4.5" angle grinder. I have given up on sharpening though. I use the brush hog for brush and fields and even the blunt blades edged with a "U" shape manage to cause just as much destruction as the razor sharp blades. If I knew I was going to be cutting only rock free grass fields where a cut appearance was required, then I would keep them sharp. Don't spend too much time sharpening them, one rock and you're back to blunt.

I've even been thinking of adding a hard facing cutting edge 1/4" thick or so with the welder since to grind a new edge on the blunt blades would require mucho material removal.

 

[Bird]

Mark, I had a little Bush Hog Squealer and had no problem removing the blades with an impact wrench that was no more powerful than yours. Then later, I had a Howse and when I removed the blades from that one the first time, I decided they must have forgotten to tighten them at the factory because it took no effort at all to remove the nuts by hand with a little adjustable wrench. I know the manuals show pretty high torque, and neither of them came from the factory with anything like more than 200 ft. lbs. I did later get an impact wrench rated at 425 ft. lbs. and used that to easily remove and replace blades.