MMM Blades

Wavewhacker

New member
Mar 30, 2015
12
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1
Henderson ,ky,usa
Trying to settle a bet about blade cutting edges location under the deck. One says it doesn't matter , the other says it does. Anyone have imput as to who is correct ? Thanks:confused::confused:
 

bucktail

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Equipment
L1500DT, 6' king kutter back blade, boom, dirt scoop ford disk JD212
Jun 13, 2016
1,232
177
63
MN
Yes, the blade location needs to be under the deck. They simply won't work on top.
 

TripleR

Active member

Equipment
BX2200, BX2660, L5740 HSTC, M8540HDC and some other tractors and equipment
Sep 16, 2011
1,911
7
38
SE Missouri
I may be misunderstanding you, but MMM blades need to be sharp, rotary cutter blades don't, they have a different edge profile.
 

CountryBumkin

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Equipment
BX2370 w/LA243, Bucket, Grapple, QA Pallet Forks, 60" MMM, rear blade & rake
Sep 27, 2015
568
2
0
Central FL
re you asking about the relationship between the different blades - meaning, how they line up with each other (like all blades facing 9 and 3 o'clock when first installed)? If that's the question, it doesn't matter.

If that is not the question, then I don't understand your question.
 

D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
On a finish mower, all MMM are, be sure to put the sharp edge closest to the grass (bottom/turf)....and keep all human parts away while they turn!

You question lacks clarity!
 

Wavewhacker

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Mar 30, 2015
12
0
1
Henderson ,ky,usa
Sorry Lads ! I was referring to the picture in the operators manual that shows blade specific placement as they correlate to each other and in relationship to the mower deck location. Thanks for the imput referring to your ideas on your present situations .:eek::eek:
 

TripleR

Active member

Equipment
BX2200, BX2660, L5740 HSTC, M8540HDC and some other tractors and equipment
Sep 16, 2011
1,911
7
38
SE Missouri
It has been a long time since I saw a MMM with specific blade orientation, it was a Massey Ferguson gear drive unit, no belts, all gear driven. It was great until you hit a solid object.
 

OBKubota

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2014Gr2120,Gr2728Snowblower,Gck5GrassCatcher,agri-FabSpreader
Oct 21, 2014
205
1
0
Ontario
Thi is from manual for my 2014 GR2120, 48" mower deck.



Sent from my iPhone using Tapatalk
 

JackJ

Member

Equipment
BX1870-1
Mar 14, 2016
264
3
18
Indiana
When I first saw that illustration in my deck manual, I was wondering if it was referencing the relative orientation, or clocking, of the blades. But I think they're only talking about changing which blade goes on which spindle in a regular rotation to keep the wear even. I.e. swap 'em out for each other in a clockwise pattern when looking from the bottom.

Seems like the blade closest to the discharge will theoretically get the most wear, as it sees the grass coming from the other blades, in addition to what it's slicing off of the lawn. But since my wear mostly comes from hitting roots, stumps, and rocks, I'm not sure the theory applies so much for me.
 

OBKubota

New member

Equipment
2014Gr2120,Gr2728Snowblower,Gck5GrassCatcher,agri-FabSpreader
Oct 21, 2014
205
1
0
Ontario
When I first saw that illustration in my deck manual, I was wondering if it was referencing the relative orientation, or clocking, of the blades. But I think they're only talking about changing which blade goes on which spindle in a regular rotation to keep the wear even. I.e. swap 'em out for each other in a clockwise pattern when looking from the bottom.



Seems like the blade closest to the discharge will theoretically get the most wear, as it sees the grass coming from the other blades, in addition to what it's slicing off of the lawn. But since my wear mostly comes from hitting roots, stumps, and rocks, I'm not sure the theory applies so much for me.


The illustration is vague but I do agree with your explanation. They spin so fast it wouldn't matter if they were pointing one way or the other. I will pay more attention to wear this fall when I service it.


Sent from my iPhone using Tapatalk
 
Last edited:

CountryBumkin

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Lifetime Member

Equipment
BX2370 w/LA243, Bucket, Grapple, QA Pallet Forks, 60" MMM, rear blade & rake
Sep 27, 2015
568
2
0
Central FL
When I first saw that illustration in my deck manual, I was wondering if it was referencing the relative orientation, or clocking, of the blades. But I think they're only talking about changing which blade goes on which spindle in a regular rotation to keep the wear even.
That's my take on the diagram too - it's like rotating the tires on your car.

But I never do this, I just remove all the blades at the same time, sharpen them, check them for balance, and reinstall. By the time I am reinstalling, I have no idea which blade came from which spindle.
 

lugbolt

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Equipment
ZG127S-54
Oct 15, 2015
4,807
1,575
113
Mid, South, USA
It doesn't matter which blade is turned in which direction. The belt always has a bit of slippage and they never return to the same orientation after running a while.

As far as left, center, and right, depends. If you mow a lot of dirt, sand, leaves...basically the stuff that wears blades faster than grass, then it's not a bad idea to rotate the discharge blade to the opposite side, then put the center blade on the discharge side. I do it during sharpening, seems to help them last a little bit longer. The discharge blade tends to wear faster as it's got to deal with the material that's discharged from the other two blades. When I see them cracked, it's almost always the discharge side blade that's worse than the other 1 or 2 depending on the deck.

Did y'all forget about the John Deere "freedom" 42" deck? The blades were connected via a timing belt, and they needed to be set in a particular orientation (timed) during belt replacement. When (not IF) the belt broke, the blades would hit each other rather spectacularly, usually resulting in blade and/or deck bending. What a pile of junk design. They cut awesome but they were junk. Tall grass would break the timing belt. Sold and installed thousands of them before we quit messing with Deere.