Mowing Mower blades can never be removed for sharpening...

[malk315]

At least that's how it is on my mower deck...

Put a block between two blades and housing on deck, put socket on blade bolt and spun bolt counter-clockwise about 2 turns and no loosening. Two out of three blades being held in place by 2x4 were not moving. Third blade was moving some of the time indicating spindle was turning rather than bolt loosening at least for part of the time.

Tried another blade -- same story.

Tried going other direction (using torque wrench set at 130 ft-lbs as manual says the blades should be torqued to) and same story.

Wish it was as easy as the owner's manual describes...

This is a DMM-60 mid-mount deck.

The blades are single bolt mount with M-16 bolt, 2 "cup" washers, one flat washer, then the blade, a "shoulder" washer, and the shoulder washer goes against the spindle.

Any recommendations? Cutting torch and buy new spindles every time I want to change blades on my $2000+ mower deck?

I don't have an impact wrench. I'm betting doing that will screw up threads or whatever.

Now I've lost confidence that the deck is safe w/ regards to blade mounting. I know they're at 130 ft-lbs (even a bit more, the range is 130 - 159), but I can turn the bolt a whole turn or more either direction and nothing will loosen.

I have a second set of blades I want to mount while I get the original set sharpened and then keep changing every once in a while.

Any of you many guys w/ RFMs have a similar blade mount? I would expect so...

Thanks in advance for any help. I really don't want to bring it back to the dealer, but I will if I have to now that I have a 16' trailer to pull it around. I'm going to make the dealer demonstrate blade removal and installation to see how he handles the nightmare.... I'm ready to start throwing tools at the concrete... absolutely ridiculous.

 

[twigpig]

I'm thinking mower blades have left hand threads. Perhaps you are turning the wrong way. Instead of lefty loosey righty tighty. It would be the other way around. They probably put them on that way so the blade turning force does not loosen them up. I am amazed at what a cheapo $25 impact wrench can do. And they sound really cool! You can probably make an improvised impact wrench out of a wrench and a hammer but I would wait until somebody posts that knows for sure which dirrection those threads go.

 

[shvl73]

A pnuematic impact is a handy tool if you have a compressor. They can be purchased inexpensively, as can a small compressor. I use a 3/8 butterfly impact on my rider mower blades.

 

[gboudreau]

check the manual to see if there is a spindle wrench for holding the spindles in place for slippage. I know my woods 3pt mower has a special tool to hold the spindles in place.

 

[malk315]

I double checked the manual -- nothing about reverse threads. It just says to loosen the blade bolts, and there is a picture of a block of wood wedged in between blade and housing w/ a wrench on the bolt w/ a pair of hands such that the bolt would be turned counter-clockwise to loosen.

My building contractor has a decent compressor and impact wrench he's been using on lag bolts. If my socket for the blade bolts (1/2" drive 22 or 23 mm socket) fits his impact wrench, I'll try rattling the bolts out with that.

I've been wanting to get a decent compressor and impact wrench for some time now (have a small compressor, but want a better one).

We'll see... stuff like this just drives me nuts. It should be simple, but never is.

 

[J_J]

I double checked the manual -- nothing about reverse threads. It just says to loosen the blade bolts, and there is a picture of a block of wood wedged in between blade and housing w/ a wrench on the bolt w/ a pair of hands such that the bolt would be turned counter-clockwise to loosen.

My building contractor has a decent compressor and impact wrench he's been using on lag bolts. If my socket for the blade bolts (1/2" drive 22 or 23 mm socket) fits his impact wrench, I'll try rattling the bolts out with that.

I've been wanting to get a decent compressor and impact wrench for some time now (have a small compressor, but want a better one).

We'll see... stuff like this just drives me nuts. It should be simple, but never is.

I am willing to bet that the blade bolts were put on with and air impact wrench, and that is what it will take to get them off. That is what I use to change my blades. You might spray them down with a bolt loosening products. Have some spare bolts in case you wring one off. I would get some impact sockets and not tear up those thin wall good s. If the blade bolts are thin head, you might have to grind off some of the impact socket to get rid of the bevel. It solved a lot of my problems.

 

[malk315]

Yep -- that's exactly what I'm thinking including getting spare bolts in case one gets wrung off from the impact wrench.

So I probably won't bother tomorrow -- I have a standard 12 point socket that would be more prone to stripping the bolt heads. I'd rather have a six-sided socket that will engage more surface of the bolt heads. In fact some of the work today w/ the torque wrench (I was using my large torque wrench since it's bigger than my normal wrenches) was starting to wear the bolt heads.

I'll just get the mowing done tomorrow and have my dealer get me a set of bolts, cup washers, and shoulder washers. It says in the manual the cup washers are a common wear item. If I have spare hardware ready when I take a shot at getting these off with an impact wrench, I won't need any of the spare parts per murphy's law.

If I try to remove the parts tomorrow (sunday) without any spare parts, one or more bolts will get wrung off or cup washers will be worn out and I won't be able to get parts til later in the week and will not be able to do my mowing.

I guess it's a prepare for the worst and still hope for the best strategy!!!

Thanks for your replies. I'm calmed down and ready to go shopping for air tools

In addition to an impact wrench, an air ratchet would be nice, and a grinder, DA sander, hmmm... Then a I'll need a welder so I have grinding to do, will need to run power out to the shed for the welder -- need a backhoe to dig the trench for that. What else....

Late night ramblings about expensive toys to buy...

 

[Egon]

Try giving the bolt a good whack or two on the end with a hammer. A good 1/2 or 3/4 inch breaker bar with socket and and a snipe for getting good force may just break it loose.