Mowing Kubota MMM blades

[Toyboy]

I just finished cleaning, changing blades and PM'ing my RCK 60B MMM. My question is I've not been able to determine if the 3 blades have a specific orientation to each other or not??? My old Case 446 deck specified an orientation but not this one that I can see. Is there a right or wrong way to install them?? Thanks

 

[Toolguy]

On mine they are all the same. I would bet money yours are, too.

 

[TripleR]

There will be notches on the spindle assemblies, so as long as you get them in the proper notches so you can tighten them down properly, you won't have any problems as they are staggered and the blades will rotate on the spindles anyway, so there really isn't any way to set them and guarantee they will stay. Torque them to about 75-80 foot pounds. This is probably to reduce shock if you hit something and reduce chances of damage. I hit a boat anchor once and no damage was done.

We had an old Massey Ferguson with gear drive as opposed to belt and the blades had to be synchronized or they would hit each other.

 

[B2400]

After 10 minutes of mowing, they will move out of orientation! Cub Cadet used to recommend the outer blades at 3 o'clock and 9 and inner blade at 6 &12. I tried this on my RCK60-24B deck and as I said, shortly thereafter they sought their own! I've never noticed any difference in quality of cut, so I no longer fuss with it!

 

[Toyboy]

I'm not sure I was clear on the blades. On the 446 they wanted the center blade in line w/bottom left blade on rotation...like tip to tip... and the same tip to tip on the bottom right when the center was rotated. So in short, the bottom left and center together would make a strait line and likewise when the center was rotated with bottom right, like two sides of a pyramid. According to Case, this orientation of the blades to each other would eliminate uncut lines. Kubota does not say anything about that as far as I can tell. The notched washer is fine and so is my torque which I set at 75#

 

[crbr]

I just finished cleaning, changing blades and PM'ing my RCK 60B MMM. My question is I've not been able to determine if the 3 blades have a specific orientation to each other or not??? My old Case 446 deck specified an orientation but not this one that I can see. Is there a right or wrong way to install them?? Thanks

Fit them back on the spindle(s), at will. There is no specified orientation.

 

[TripleR]

I'm not sure I was clear on the blades. On the 446 they wanted the center blade in line w/bottom left blade on rotation...like tip to tip... and the same tip to tip on the bottom right when the center was rotated. So in short, the bottom left and center together would make a strait line and likewise when the center was rotated with bottom right, like two sides of a pyramid. According to Case, this orientation of the blades to each other would eliminate uncut lines. Kubota does not say anything about that as far as I can tell. The notched washer is fine and so is my torque which I set at 75#

Yes, you were clear, but no matter how you set your blades there is nothing to keep them from rotating on the spindle other than friction and when/if this happens, it won't affect anything. I got mine back from the dealer once and while doing a check on my blades noticed the one on the left could be rotated by hand and the cut quality was still good with no strips. I put it in my garage and torqued it where it was.

I have had mowers with keys or stars in the blade to prevent rotation, but there is nothing on the Kubota like this.

 

[Toyboy]

OK, gotcha.:thumbsup: Just thought I'd check it out. Thanks to all.

 

[David_Kb7uns]

The only thing that I have seen in some Kubota manuals, is after each sharpening to rotate the blades as to which spindle they are mounted on so you can kind of balance the wear on the blades.

David Kb7uns

 

[Toyboy]

I spotted that but was in a quandary about orientation which has been cleared up.:thumbsup:
What do you guys fine best to use on the spline shaft..... grease or never seize? I'm leaning towards never seize.

My big problem is that the machine was delivered to me with snow blower mounted and we don't have any snow!!! So now I've got way too much time on my hands to sit around and think of all this goofy stuff The darn thing is all dressed up with no place to go until switch over from snow to grass So in the meantime I've been PM'ing everything I can think of:laughing:

 

[Toyboy]

I spotted that but was in a quandary about orientation which has been cleared up.:thumbsup:
What do you guys find best to use on the spline shaft..... grease or never seize? I'm leaning towards never seize.

My big problem is that the machine was delivered to me with snow blower mounted and we don't have any snow!!! So now I've got way too much time on my hands to sit around and think of all this goofy stuff The darn thing is all dressed up with no place to go until switch over from snow to grass So in the meantime I've been PM'ing everything I can think of:laughing:

 

[TripleR]

If you are talking about the threads on the spindle, I don't use anything.

I know what you mean, I also have a new tractor and it is too muddy to do anything with it.

 

[jimmer2880]

I use Neversieze on everything that doesn't get locktite.

 

[rdsaustintx]

 

[Toyboy]

I was referring to the drive (slip?) splines connecting the front PTO to the MMM drive or the snow blower. I think jimmer 2880 may have answered my question though.

 

[aczlan]

I have had mowers with keys or stars in the blade to prevent rotation, but there is nothing on the Kubota like this.

Generally those are not found on commercial grade mowers, only on cheaper ones as commercial mowers are designed with the idea that you will hit stuff and hitting stuff does bad things to the star castings.
I have never had an issue with a properly torqued blade coming loose. I once had an Exmark where the guy running it hit a water shutoff valve casing (nice heavy 1/2" walled steel casting) and jammed the bolt on so hard that we had to heat it with an oxy-acetylene torch to get it off. None of our impact wrenches would touch it, nor would a 5' cheater pipe on the breaker bar. We ended up replacing the spindle and the bearing as the spindle got hot and we didnt want to risk it shattering down the road.


Aaron Z

 

[rdsaustintx]

The star washer keeps torque from transmitting to the blade mounting bolt only. The blade is not keyed to the spindle shaft.

Torque to the blade itself is transmitted by friction with the bellville washers ("cup washers" in Bota lingo). This protects the spindle and drivetrain by allowing the blade to slip if you hit an immovable object.

edit: For the RCK60 deck. I don't know anything about others.

 

[aczlan]

The star washer keeps torque from transmitting to the blade mounting bolt only. The blade is not keyed to the spindle shaft

That depends on the deck. I have a Cub Cadet LT1050 which has the stars built into the end of the spindle shaft.
We should really replace it with a commercial mower given the amount of mowing we do, but that is a decision that isnt mine to make.

Aaron Z

 

[David_Kb7uns]

My big problem is that the machine was delivered to me with snow blower mounted and we don't have any snow!!! So now I've got way too much time on my hands to sit around and think of all this goofy stuff The darn thing is all dressed up with no place to go until switch over from snow to grass So in the meantime I've been PM'ing everything I can think of:laughing:

Well I did hear of a snow blower used to spread manure but not sure how it cuts grass. I suppose next year you can try mowing the snow until it gets too deep.
Around here somebody flipped on the sun switch and now we get to mow the grass twice a week.

David Kb7uns