MMM Vertical Travel Limited

[Skypilota72]

I own a Mahindra Max 24, and am having midmount mower deck hydraulic lift issues.

I have both removed and attached the MMM many times throughout the years without issue, but this springtime attachment has me puzzled.

The MMM shares the same link functionality with the rear 3PH, and is supposed to fully lift or lower both 3PH and MMM fluidly based on the travel of the control.

Lately, the 3PH works great, but the MMM does not lift until near the top of it's cycle, and the MMM distance lifted is only an inch.

All attach points are fine. The rear MMM lift brackets are adjusted correctly, although I cannot seem to get the deck horizontally leveled with the ground. I cannot see any points that are binding either. Unless my MMM forward harness is somehow bent, which doesn't seem likely, I just can't figure this out.

Something must be binding or misaligned, but nothing appears obvious. It days like this I wished I had bought a tow behind vs an MMM.

 

[doneill127]

What do you have the pin for the mowing height set at. If it’s in the 3.5-4 hole, there will not be much more vertical lift before it hits the stops.

 

[Skypilota72]

I have tried all positions. It operates as though it is set in the 3.5/4 holes, and changes make no difference.

Looking at the back of the pin dial (seat forward) I can see the cascading positions working, with exception to the 4”. This one appears blocked.

Edit:
The hight adjustment wheel will not set to the pin settings for "Install" "3.5" or "4". It is blocked from turning further.

 

[coldsteelva]

Since the MMM lift arms are physically tied to and limited by the travel of the 3PH arms, make sure there is no binding in the 3PH. I had the opposite problem of the MMM not dropping to the appropriate level and it was because one of the implement arms was binding and holding up the 3PH.

 

[Skypilota72]

Since the MMM lift arms are physically tied to and limited by the travel of the 3PH arms, make sure there is no binding in the 3PH. I had the opposite problem of the MMM not dropping to the appropriate level and it was because one of the implement arms was binding and holding up the 3PH.

So, the round height knob will only allow full travel (Setup to 3.5”) when there is no weight on the support arms of the MMM. I removed the MMM (knob now had full motion), I set the knob to 2” and reattached the MMM. No difference in operation. The knob seemingly is not the problem. The MMM hangers for the support arms are not binding either.

Moving the seat forward allowed me to observe the connected linkages, which did not appear bound or bent.

This seemingly may be beyond my ability to fix. The only advantage is it is fully usable and set to the correct height to cut the grass. It would be nice to have full control, but this will do for now.

 

[Skypilota72]

So, the round height knob will only allow full travel (Setup to 3.5”) when there is no weight on the support arms of the MMM. I removed the MMM (knob now had full motion), I set the knob to 2” and reattached the MMM. No difference in operation. The knob seemingly is not the problem. The MMM hangers for the support arms are not binding either.

Moving the seat forward allowed me to observe the connected linkages, which did not appear bound or bent.

This seemingly may be beyond my ability to fix. The only advantage is it is fully usable and set to the correct height to cut the grass. It would be nice to have full control, but this will do for now.

Almost forgot the question here… Yes, the 3PH has always had full, smooth and graduated movement.

 

[tmcj]

Not sure about the 24 but my 26xl has a bracket on each side that floats with the arms. They are pinned up when not using the mower. If you don't pull the pins the deck doesn't drop or raise correctly with the arms.

 

[Skypilota72]

Not sure about the 24 but my 26xl has a bracket on each side that floats with the arms. They are pinned up when not using the mower. If you don't pull the pins the deck doesn't drop or raise correctly with the arms.

My Americorp MMM should be identical with your XL, albeit mine is a 60” and yours is a 72”.

The brackets on mine are attached in the same way as yours, The MMM being supported by those brackets laterally, and the nose bracket from the forward hook brackets to the front frame of the tractor in a triangle format.

I am not sure what other brackets should be there while using or not while using the MMM as you have described, but am very interested to hear further.

I am also wondering if the forward bracket is perhaps slightly twisted, as I often use it on a small incline running laterally. This causes the deck to ‘bridge’ itself and angle out of the tractors alignment. As the forward bracket is rigid, this may be a possibility. I'll know more today as I remove the forward bracket and work the 3PH, looking for travel of the rear supports.
.

 

[Skypilota72]

Ok, found something interesting. With the front bracket removed, I get full movement of the left rear MMM bracket and only half on the right rear MMM bracket.

The 3PH has its MMM attach point on the left rear side only, that moves a shaft, supplying lift to both rear brackets.

This shaft is not split, so equal movement on both ends would need to take place, and was confirmed by observation. The right rear bracket is properly attached to the shaft and pinned into place. Yet, does not have full travel. If the attach point pins were broken on the right side, the weight on the MMM would not allow any movement at all for that side.

Using a Laser Plumb, it's absolutely obvious that the right side bracket arm (attached to shaft) moves later than the left and only partially.
Somewhere, most likely at the shaft and attachment arm on the right side is a damaged pin or something.

FYI: The laser plumb is pointed exactly across from both attach points. The camera is angled to better see the red dots.

 

[Skypilota72]

Schematic Attached